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The Southern Residents are actually a large extended family, or clan, comprised of three pods: J, K, and L pods. Within each pod, families form into subpods centered around older females, usually grandmothers or great-grandmothers. Both male and female offspring remain in close association with their mothers for life.
As of July 1, 2010, the population totals 87* individuals (not including Lolita at Miami Seaquarium). All three Southern Residents pods were reduced in number during 1965-75 as a result of captures for marine parks. At least 13 orcas were killed during captures, and 45 were delivered to marine parks around the world, of which only Lolita remains alive.
The Southern Residents are often seen during the summer in the protected inshore waters of the Salish Sea, especially in Haro Strait, west of San Juan Island, in the Strait of Juan de Fuca, and Georgia Strait near Fraser River. This overall inland sea is known as the Salish Sea.
Each pod uses a characteristic dialect of calls to communicate, with certain calls used in common between pods. The calls used by the Southern Community are unlike the calls made by any other community of orcas. These calls can travel ten miles or more underwater.
J POD, with 28 members, is the pod most likely to appear year-round near the San Juan Islands, in the lower Puget Sound near Seattle, and in Georgia Strait at the mouth of the Fraser River. J pod tends to frequent the west side of San Juan Island in mid to late spring.The oldest member of J pod is J2, estimated to be in her nineties. J pod's mature males are J1, J26, J27 and J30 and two nearly matured males J33 and J34 .
K POD now has 20 members. The matriarch of K pod is K11, also estimated to be in her nineties. K pod has two mature males, K21, and K26, and one nearly matured male K25.
L POD, with 39 members, is by far the largest resident pod. L pod's mature males are L41, L78 and L79, nearly mature are L89 and L87.
The Southern Residents' diet, range, social behavior, kinship system and linguistic system are distinct from other orca populations that occur in the Pacific Northwest. In addition to the Southern Resident Community, there is a Northern Resident Community (Northern B.C.), a Transient Community, and an Offshore Community. Pods from one community have never been observed traveling with those from another community, although their ranges partly overlap. The call dialects of the four communities are also distinct.
The Northern Resident Community, which is found primarily in the Johnstone Strait area and northern British Columbia, is made up of about 220 whales in 16 pods. The Northern and Southern Residents are fully described in Killer Whales by Ford, Ellis, and Balcomb from UBC/UW Press.
Another community of orcas, called Transients, can be found in small groups from Mexico to the Bering Sea. They appear only occasionally in the Salish Sea, usually near Vancouver Island. Transients specialize in a diet of marine mammals, especially seals, sea lions, and porpoises. There are about 170 transients, but they travel in small groups of one to five individuals, staying close to shorelines, often near seal rookeries when pups are weaned.
In 1991 another community, called Offshores, was discovered. These whales may be the ancestral population of the Northern and/or Southern Residents. They are most often seen in the Pacific Ocean, 15 to 25 miles out at sea, off Vancouver Island and the Queen Charlottes, though members of this community have been seen from southern California to the Bering Sea.
* The population number cited on this website is for the general public, and is provided as an estimate only. As the number of whales in this population is constantly changing, please contact the Center for Whale Research directly prior to any publication of this estimate to receive the most current information. Any published or broadcast reference to this population estimate must include credit to the Center for Whale Research. Thank you.
This pages contains information and links to articiles and incidents involving Navy sonar use and marine mammals.
One report that is not related to Killer whales specifically, but that is particularly close to our heart, is the following:
A Mass Stranding of Cetaceans Caused by Naval Sonar in the Bahamas.
by Kenneth C. Balcomb III
and Diane E. ClaridgeFirst published in:
The Bahamas Journal of Science.
Volume 8, Number 2. May 2001.
A Mass Stranding of Cetaceans Caused by Naval Sonar in the Bahamas.
Kenneth C. Balcomb III and Diane E. Claridge
With the advent of powerful military sonar systems in recent decades, worldwide attention has focused on the potential effects of sonar on whale behavior and survival, with particular concern over the coincidence of Beaked whale (Order Cetacea, Suborder Odontoceti, Family ZiphiiDae) mass strandings concurrent with or following naval maneuvers. In this report we provide documentation and discussion of a very significant multi-species mass stranding of cetaceans, predominantly beaked whales, in the northern Bahamas on March 15, 2000, coincident with a U.S. and allied naval transit through the area.
To hear a recording of Navy Sonar click HERE »
This sample of modern mid-frequency sonar was recorded by hydrophone in Haro Strait May 5, 2003 during a US navy exercise. Please turn down your speaker before listening.
Navy Sonar in Puget Sound, May 5, 2003:
This is a statement released by Ken Balcomb,
Director and Principal Investagator of the Center for Whale Research
May 12, 2003
On 5 May 2003, the US Navy Guided Missile Destroyer "Shoup" DDG 86 conducted sonar operations for five hours in the Strait of Juan de Fuca and in Haro Strait between Vancouver Island, creating one of the most obvious displays of marine mammal harassment that experienced observers have ever seen, anywhere. The terrorized whales and porpoises in the region could not escape the intense mid-frequency (3 kHz) long duration "pings" from the ship's SQS 53C sonar; and, several porpoises are reported to have "coincidentally" stranded and died following the sonar event. The carcasses of these mammals have been collected for forensic examination for acoustic pressure trauma (bleeding in ears and brain).
By chance, J pod of 22 killer whales was in Haro Strait at the time of the sonar operations. Observers noted that they abruptly stopped their feeding and gathered in a tight group to swim close to shore at the surface for the duration of the sonar exercise. The sonar "pings" were so powerful (>200 dB re 1 uPa) that they could be heard in air by visitors along the shoreline of San Juan Island.
The US Navy is seeking exemption from the Endangered Species Act and the Marine Mammal Protection Act in Congress this week, in part because they know they are the most egregious of marine mammal harassers and killers worldwide. Since March 2000, when they chased 17 whales ashore in the Bahamas, the Navy has known that their sonar kills and injures whales at distances well beyond the visual horizon, yet they continue to "exercise" in inappropriate and confined waters killing these innocent animals.
In just this one day that we recently videotaped, the Navy's lethal sonar adversely impacted every marine mammal within twenty miles of the ship. No wonder marine mammals are stranding and their populations are declining. This is a literal "no-brainer" for the Navy and the whales.
Ken Balcomb
Center for Whale Research
• For more information about the May 5, 2003 incident go to:
Orca Network: News_Navy Sonar
• Supreme court ruling on Navy sonar:
Natural Resource Defense Council (NRDC):NRDC/Press Release- Supreme Court Limits Protection for Whales from Navy Sonar November 12, 2008.
On this page, we provide abstracts (and in some cases the entire document) of numerous published scientific papers and reports.
1 • Morton, A.B., J.C. Gale. and R.C. Prince. (1986). Sound and behavioral correlation in captive Orcinus orca. In: Kirkevold, B.C. and Lockhard, J.S. (eds.) Behavioral biology of killer whales.
ABSTRACT»
2 • Moore, S. E. (Sea World Research Institute, Hubbs Marine Research Center), J. K. Francine (Sea World Research Institute, Hubbs Marine Research Center), A. F. Bowles (Sea World Research Institute, Hubbs Marine Research Center), and J. K. B. Ford (Vancouver Aquarium). (1988). Analysis of calls of killer whales (Orcinus orca) from Iceland and Norway.
ABSTRACT»
3 • Ford, J. K. B. (1991). Family Fugues.
ABSTRACT»
4 • Deecke, V.B. (1998). Stability and Change of killer whale (Orcinus orca) dialects.
ABSTRACT»
5 • Deecke, V.B., J.K.B. Ford, P. Spong. (1999). Quantifying complex patterns of bioacoustic variation: Use of a neural network to compare killer whale (Orcinus orca) dialects.
ABSTRACT»
6 • Deecke, V.B., Ford, J.K.B., and Spong, P. (2000). Dialect Change in Resident Killer Whales (Orcinus orca): Implications for Vocal Learning and Cultural Transmission.
ABSTRACT»
7 • Miller, Patrick J. O. (Biology Department, Woods Hole Oceanographic Institution), David E. Bain (Animal Behavior Program, University of Washington, Seattle). (2000). Within-pod variation in the sound production of a pod of killer whales, Orcinus orca.
ABSTRACT»
8 • Yurk, Harald. (2001). Parallel cultural and genetic lineages in Alaskan resident type killer whales.
ABSTRACT»
9 • Erbe, Christine. (2002). Underwater noise of whale-watching boats and potential effects on killer whales (Orcinus orca) based on an acoustic impact model (2002).
ABSTRACT»
10 • Miller, P. (2002). Mixed-directionality of killer whale stereotyped calls: a direction of movement cue?
ABSTRACT»
11 • Au, Whitlow W. L., John K. B. Ford, John K. Horne, Kelly A. Newman Allman. (2004). Echolocation signals of free-ranging killer whales (Orcinus orca) and modeling of foraging for chinook salmon (Oncorhynchus tshawytscha).
ABSTRACT»
12 • Andrew D. Foote, Richard W. Osborne and A. Rus Hoelzel (2004). Whale-call response to masking boat noise.
ABSTRACT»
13 • Miller, Patrick J.O., A.D. Shapiro; P.L. Tyack & A.R. Solow. (2004). Call-type matching in vocal exchanges of free-rangingresident killer whales, Orcinus orca.
ABSTRACT»
14 • Saulitis, Eva L.; Matkin, Craig O.; Fay, Francis H. (2005). Vocal repertoire and acoustic behavior of the isolated AT1 killer whale subpopulation in southern Alaska.
ABSTRACT»
15 • Foote, Andrew D., Rachael M. Griffin, David Howitt, Lisa Larsson, Patrick J. O. Miller and A. Rus Hoelzel. (2006). Killer whales are capable of vocal learning.
ABSTRACT»
16 • Oleson, Erin M., Sean M. Wiggins, and John A. Hildebrand (2006). Acoustic monitoring of resident, offshore, and transient killer whales off the Washington coast.
ABSTRACT»
17 • Simon, Malene, Fernando Ugarte, Magnus Wahlberg, and Lee A. Miller. (2006). Icelandic killer whales (Orcinus orca) use a pulsed call suitable for manipulating the schooling behaviour of herring (Culpea harengus).
ABSTRACT»
18 • Filatova O.A., Fedutin I.D., Burdin A.M., Hoyt E. (2007). The structure of the discrete call repertoire of killer whales Orcinus orca from Southeast Kamchatka Bioacoustics.
ABSTRACT»
19 • Morisaka, T., R. C. Connor (2007). Predation by killer whales (Orcinus orca) and the evolution of whistle loss and narrow-band high frequency clicks in odontocetes.
ABSTRACT»
20 • Rehn, Nicola; Teichert, Stefanie; Thomsen, Frank. (2007). Structural and temporal emission patterns of variable pulsed calls in free-ranging killer whales (Orcinus orca).
ABSTRACT»
21 • Simon, Malene, Magnus Wahlberg, and Lee A. Miller. (2007). Echolocation clicks from killer whales (Orcinus orca) feeding on herring (Clupea harengus) (L).
ABSTRACT»
22 • Simon, Malene, Peter K. McGregor, and Fernando Ugarte (2007). The relationship between the acoustic behaviour and surface activity of killer whales (Orcinus orca) that feed on herring (Clupea harengus).
ABSTRACT»
23 • Holt, M.M. (2008). Sound Exposure ad Southern Resident Killer Whales (Orcinus orca): Current Knowledge ad Data Gaps. NOAA Tech. Memo. NMFS-NWFSC-89, 59 p.
PDF»
Abstracts
1) Morton, A.B., J.C. Gale. and R.C. Prince. (1986). Sound and behavioral correlation in captive Orcinus orca. In: Kirkevold, B.C. and Lockhard, J.S. (eds.) Behavioral biology of killer whales. Alan R. Liss, Inc. New York. pp.
Abstract
The relationship between cetacean sounds and behaviors has been a topic of interest, frustration and confusion. The traditional approach attempted to correlate the occurrence of a sound with a specific behavior, e.g., as in the case of obvious behavioral stress and the emission of a "distress whistle" (Busnell and Driedzic, 1968; Caldwell and Caldwell, 1971; Wood, 1954). While the results have been positive they have also been inconclusive. A sound might be highly correlated with a particular activity but it might also be evinced in apparently unrelated activities. Thus with this method no definite pattern is ascertained.
In this study we looked at the percentage emission rather than the absolute occurrence of sounds. Instead of concentrating on one or two individual sounds we took a broad look at the overall usage of the sound in different behavioral activities of Orcinus orca. With this approach a relationship was found between sounds and behavioral states, i.e., "tranquility," "play" and "distress."
2) Moore, S. E. (Sea World Research Institute, Hubbs Marine Research Center), J. K. Francine (Sea World Research Institute, Hubbs Marine Research Center), A. F. Bowles (Sea World Research Institute, Hubbs Marine Research Center), and J. K. B. Ford (Vancouver Aquarium). (1988). Analysis of calls of killer whales (Orcinus orca) from Iceland and Norway. Rit Fiskideildar Vol. 11, p. 225-250.
Abstract
Underwater recordings of killer whale calls were made off Norway and Iceland from 1983 through 1986 in association with efforts to photograph dorsal fins and saddles for identification of individual whales. Researchers collected eight hours of recordings near at least two pods off Norway and eight hours of recordings near at least five pods off Iceland. A preliminary description of discrete call types for whales from each area was completed using methods developed on well known pods of killer whales off British Columbia and Washington. Twenty-four discrete calls were described for whales off Iceland; 23 discrete call types were identified for whales off Norway. There was little evidence of calls shared between Icelandic and Norwegian pods.
Note: Sonograms of calls made in 1998 by Keiko (of Free Willy fame) were compared with the above calls and found to significantly match them, indicating Keiko has retained the ability to communicate vocally with his natal family.3) Ford, J. K. B. (1991). Family Fugues. Natural History, March, 1991, p. 68-76.
Abstract
Quote: "Like all members of the dolphin family, killer whales rely heavily on underwater sound for both navigation and communication."
"After recording the whales on many occasions over several years, I learned that most resident pods repetitively emit about a dozen different types of what I term discrete calls—each distinct enough to be identified by ear."
"Whenever a pod is routinely foraging or traveling, calls tend to be stereotyped, varying only slightly in duration or pitch. Some situations create excitement among the whales, however, such as when two pods meet after an extended period of separation. Then vocal activity is often intense, and the calls produced tend to be higher in pitch, shorter in duration, and repeated more rapidly than the same calls given by relaxed or resting whales. And when whales are interacting physically-chasing, pushing, and nipping each other-or when juveniles play together, they incorporate many abberrations into their normal calls and emit an array of squeaks, squawks, and whistles that are seldom, if ever, repeated in the same form."
"In more than seventeen years of study, no whale has yet been seen to transfer permanently from one group to another. The pods bulls-once thought to be the breeding 'harem masters' of the group-are simply the mature male offspring of the females in the pod."
"As the new pods spent more and more time apart and developed their own social identities, their repertoires of calls began gradually changing through a process of cultural drift."
"Dialects, too are slow to change. The southern community pod J1, for example, is making the same calls today as in 1958, when the Canadian navy made recordings."
"What, if any, function is served by vocal dialects in killer whales is not certain."
"I'm sure individuals are able to identify whales from other pods by their dialects, but I suspect that more information than simple pod affiliation is exchanged."
"With luck and perseverence, we may eventually be able to construct a global lexicon for this most exceptional species”.4) Deecke, V.B. (1998). Stability and Change of killer whale (Orcinus orca) dialects. M.Sc. thesis, The University of British Columbia, Vancouver, B.C., 114 pp.
Abstract
Vocal dialects have been described in many species, but most studies so far have focused on territorial species such as songbirds and humans. This study investigates patterns of structural variation in the stereotyped calls of 9 matrilineal units of killer whales (Orcinus orca ) with congruent home ranges.
In Chapter I, I describe an index of acoustic similarity based on neural network analysis of frequency contours. I test this index on simulated signals, and compare it to similarity ratings from three human subjects. The index could discriminate along global differences in contour frequency, as well as localized differences in frequency and shape. It rated similarity comparably to humans, since differences between ratings among subjects exceeded differences between subject ratings and the neural network index.
In the second Chapter, I analyse 2 call types used by 2 groups over a 12 year period to identify mechanisms of vocal differentiation. A test for structural modification detected significant changes in one call type in both groups, but not in the other. The rate of differentiation between both groups was significantly lower for the modified call type than the rate of modification in one group showing that modifications are transmitted between groups. Results of an analysis of structural parameters are consistent with a theory of structural drift.
In Chapter III, I quantify patterns of structural variation for 4 call types shared by 9 matrilineal units. Patterns are consistent across some call types, and similarity ratings for two call types are correlated with the frequency of association among groups. This presents additional evidence for the role of cultural transmission in maintaining structural similarity of shared calls.
This study shows that discrete calls of killer whales are modifiable behavioural traits and transmitted through learning. Since multiple vocal traditions persist in spite of frequent acoustic contact between their members, this study presents evidence for selective copying in resident killer whales. If association patterns reflect kinship among matrilineal units as they do among individuals and among communities, similarity of shared call types indicates the degree of maternal relatedness, and may function in kin recognition or mate choice.5) Deecke, V.B., J.K.B. Ford, P. Spong. (1999). Quantifying complex patterns of bioacoustic variation: Use of a neural network to compare killer whale (Orcinus orca) dialects. Journal of the Acoustical Society of America. Vol.105 i4, p. 2499-2507.
Abstract
A quantitative measure of acoustic similarity is crucial to any study comparing vocalizations of different species, social groups, or individuals. The goal of this study was to develop a method of extracting frequency contours from recordings of pulsed vocalizations and to test a non-linear index of acoustic similarity based on the error of an artificial neural network at classifying them. Since the performance of neural networks depends on the amount of consistent variation in the training data, this technique can be used to assess such variation from samples of acoustic signals. The frequency contour extraction and the neural network index were tested on samples of one call type shared by 9 social groups of killer whales. For comparison, call similarity was judged by 3 human subjects in pairwise classification tasks. The results showed a significant correlation between the neural network index and the similarity ratings by the subjects. Both measures of acoustic similarity were significantly correlated with the groups' association patterns, indicating that both methods of quantifying acoustic similarity are biologically meaningful. An index based on neural network analysis therefore represents an objective and repeatable means of measuring acoustic similarity, and allows comparison of results across studies, species, and time.6) Deecke, V.B., Ford, J.K.B., and Spong, P. (2000). Dialect Change in Resident Killer Whales (Orcinus orca): Implications for Vocal Learning and Cultural Transmission. Anim. Behav.60(5):619-638.
Abstract
Variation in vocal signals among populations and social groups of animals provides opportunities for the study of learning and its importance in generating and maintaining variation in behavioural traits. In this study, we analyse 2 call types made by 2 matrilineal social groups of resident killer whales (Orcinus orca) over a period of 14 years. We use a neural network-based index of acoustic similarity to identify mechanisms of call differentiation. A test for structural modification of the calls detected significant changes in one call type in both groups, but not in the other. For the modified call type, the rate of differentiation between the two groups was significantly lower than the rate of modification within either group showing that calls are modified in a similar fashion in the two groups. An analysis of structural parameters detected no strong directionality in the change. The detected pattern of call modification could be caused by maturational changes to the calls, or, if killer whale dialects are learned behavioural traits, cultural drift in the structure of the calls together with horizontal transmission of modifications between the two groups. Such vocal matching between members of different matrilineal groups would suggest that vocal learning is not limited to vertical transmission from mother to offspring, as required for some models of gene-culture coevolution.7) Miller, Patrick J. O. (Biology Department, Woods Hole Oceanographic Institution), David E. Bain (Animal Behavior Program, University of Washington, Seattle). (2000). Within-pod variation in the sound production of a pod of killer whales, Orcinus orca. Animal Behaviour, Vol. 60, No. 5, Nov. 2000, pp. 617-628.
Abstract
Pod-specific calling behaviour of resident killer whales has been shown to include: discrete call types not shared among pods, different production rates of shared call types, and differences in the detailed structure of shared call types. To investigate the mechanisms leading to pod-specific calling, we compared the repertoire and structure of calls produced by three different matrilineal units within the same pod, and described call features encoding matrilineal-unit distinctiveness. The three matrilineal units had different production rates of shared calls, including one call type used almost exclusively by one matrilineal unit. Cross-validated discriminant function analyses revealed matrilineal-unit distinctive structure in five of the six shared call types examined, with duration of the terminal component being the most distinctive feature for all call types containing a terminal component. Calls generally consist of low- and high-frequency components that may follow different time-frequency contours. In our sample, a particular high-frequency contour was consistently paired with a particular low-frequency contour, both contours had roughly equal overall variability, and each contained independent matrilineal-unit distinctive information. The only call type that did not differ structurally between matrilineal units is reportedly used more in interpod meetings than in intrapod contexts. The differences in calling behaviour between matrilineal units were similar in form to previously described differences between pods, although more subtle. These results suggest that pod-specific calling behaviour in resident killer whales arises primarily as a consequence of accumulated drift or divergence between highly cohesive matrilineal units as they gradually separate into different pods.8) Yurk, Harald. (2001). Parallel cultural and genetic lineages in Alaskan resident type killer whales. Marine Mammal Research Unit, Department of Zoology, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.
Abstract
We present evidence that at least two acoustically and genetically distinct clans (vocally related pods) of resident killer whales inhabit Prince William Sound, Alaska. We compared the sound contours of approximately 9000 calls from 480 recording sessions of six photo identified killer whale pods. The pods fell into two acoustically distinct clans, with no evidence of sharing of call types between them. One clan referred to as AB-clan, included AB AI and AN pods. The second clan, AE-clan, included AD, AE and AK pods. We identified a mean number of 12 distinct call types for each pod, based predominantly on pulsed tone components. Call types and their variants were shared among member pods of the same clan. A dendogram based on a quantitative index of acoustical similarity shows that within AB-clan, AB, AI and AN pods are vocally more similar to each other than either is to AJ pod. Within AD-clan, AD, AE and AK pods are equally similar. Using DNA from biopsy samples, we sequenced the entire mitochondrial region control region of 16 AB-clan and 12 AE-clan individuals, including members of each pod. Each clan was monomorphic for a single haplotype and the two clans differed by one transition. It thus appears that the acoustic differences between the clans, which we presume to be cultural, are distinct clans (vocally related pods) of resident killer whales inhabiting Prince William Sound, Alaska.
Note: Yurk has found that the resident killer whales of Alaska have vocal traditions or cultural lineages that match maternal lineages as proposed by Dr. Ford earlier. This is the first time that direct evidence for the existence of parallel cultural and genetic lineages has been found in a non-human society.9) Erbe, Christine. (2002). Underwater noise of whale-watching boats and potential effects on killer whales (Orcinus orca) based on an acoustic impact model (2002). Marine Mammal Science, Volume 18 Issue 2 Page 394-418.
Abstract
Underwater noise of whale-watching boats was recorded in the popular killer whale-watching region of southern British Columbia and northwestern Washington State. A software sound propagation and impact assessment model was applied to estimate zones around whale-watching boats where boat noise was audible to killer whales, where it interfered with their communication, where it caused behavioral avoidance, and where it possibly caused hearing loss. Boat source levels ranged from 145 to 169 dB re 1 μPa @ 1 m, increasing with speed. The noise of fast boats was modeled to be audible to killer whales over 16 km, to mask killer whale calls over 14 km, to elicit a behavioral response over 200 m, and to cause a temporary threshold shift (TTS) in hearing of 5 dB after 30–50 min within 450 m. For boats cruising at slow speeds, the predicted ranges were 1 km for audibility and masking, 50 m for behavioral responses, and 20 m for TTS. Superposed noise levels of a number of boats circulating around or following the whales were close to the critical level assumed to cause a permanent hearing loss over prolonged exposure. These data should be useful in developing whale-watching regulations. This study also gave lower estimates of killer whale call source levels of 105–124 dB re 1 μPa.10) Miller, P. (2002). Mixed-directionality of killer whale stereotyped calls: a direction of movement cue?
Abstract
The functional and ecological consequences of the directional emission of sounds used for communication remain largely unexplored even though non-uniform radiation patterns have been reported across a wide range of taxa. In this study the spectral structure of stereotyped calls recorded from groups of travelling killer whales (Orcinus orca) moving consistently toward or away from a towed hydrophone array was measured by comparing the energy in high-frequency (>5 kHz) with that in low-frequency (1–5 kHz) bands. Relative energy in high-frequency bands was significantly greater when animals were moving toward the hydrophone array, but only in call types that contain a separately modulated high-frequency component. The difference in relative energy as a function of direction of movement was more than 10 dB at the fundamental frequency of the high-frequency component of the two most common types recorded, confirming a strong pattern of mixed-directionality in these calls. Changes in call spectra due to signaler orientation to a receiver may provide an intrinsic cue of a moving signaler's direction of movement. Killer whales have sensitive hearing over the frequency range of this potential cue, and their marked behavioral synchrony suggests its use. The direction of movement cue inherent in the directionality pattern of calls may be an efficient and reliable means for this and possibly other highly mobile species to coordinate behavior and regu-late spacing relative to other individuals.11) Au, Whitlow W. L., John K. B. Ford, John K. Horne, Kelly A. Newman Allman. (2004). Echolocation signals of free-ranging killer whales (Orcinus orca) and modeling of foraging for chinook salmon (Oncorhynchus tshawytscha). The Journal of the Acoustical Society of America — February 2004 — Volume 115, Issue 2, pp. 901-909.
Abstract
Fish-eating "resident"-type killer whales (Orcinus orca) that frequent the coastal waters off northeastern Vancouver Island, Canada have a strong preference for chinook salmon (Oncorhynchus tshawytscha). The whales in this region often forage along steep cliffs that extend into the water, echolocating their prey. Echolocation signals of resident killer whales were measured with a four-hydrophone symmetrical star array and the signals were simultaneously digitized at a sample rate of 500 kHz using a lunch-box PC. A portable VCR recorded the images from an underwater camera located adjacent to the array center. Only signals emanating from close to the beam axis (1185 total) were chosen for a detailed analysis. Killer whales project very broadband echolocation signals (Q equal 0.9 to 1.4) that tend to have bimodal frequency structure. Ninety-seven percent of the signals had center frequencies between 45 and 80 kHz with bandwidths between 35 and 50 kHz. The peak-to-peak source level of the echolocation signals decreased as a function of the one-way transmission loss to the array. Source levels varied between 195 and 224 dB re:1 µPa. Using a model of target strength for chinook salmon, the echo levels from the echolocation signals are estimated for different horizontal ranges between a whale and a salmon. At a horizontal range of 100 m, the echo level should exceed an Orcinus hearing threshold at 50 kHz by over 29 dB and should be greater than sea state 4 noise by at least 9 dB. In moderately heavy rain conditions, the detection range will be reduced substantially and the echo level at a horizontal range of 40 m would be close to the level of the rain noise.
12) Andrew D. Foote, Richard W. Osborne and A. Rus Hoelzel (2004). Whale-call response to masking boat noise. Nature 428, 910 (29 April, 2004).
Abstract
Background noise can interfere with the detection and discrimination of crucial signals among members of a species. Here we investigate the vocal behaviour in the presence and absence of whale-watcher boat traffic of three social groups (pods) of killer whales (Orcinus orca) living in the nearshore waters of Washington state. We find longer call durations in the presence of boats for all three pods, but only in recent recordings made following a period of increasing boat traffic. This result indicates that these whales adjust their behaviour to compensate for anthropogenic noise once it reaches a threshold level.13) Miller, Patrick J.O., A.D. Shapiro; P.L. Tyack & A.R. Solow. (2004). Call-type matching in vocal exchanges of free-rangingresident killer whales, Orcinus orca. Animal Behaviour, 2004, 67, 1099e1107doi:10.1016/j.anbehav. 2003.06.017.
Abstract
Previous sound recordings of resident (fish-eating) killer whale groups have revealed matrilineal group-specific call repertoires and a strong tendency for calls of the same type to be produced in series. Vocalinteractions between individual free-ranging animals, however, have remained unexplored because it hasnot been possible to identify signallers reliably with a single hydrophone. Here we link acoustic arrivals ofcalls on a towed hydrophone array with visual tracking of photo-identified individuals to ascribe calls toa focal animal when it was separated from other members of its matrilineal group by more than 35 m, andthereby out of visual range. We confirm that individual members of a matrilineal group share a repertoireof stereotyped calls, and we statistically examine timing of stereotyped calls produced by one individualrelative to calls produced by other members of its group. Analysis of the intervals between stereotyped callsindicated that calls were produced in group bouts with a criterion interval of 19.6 s separating bouts. Wewere therefore careful to develop randomization tests that preserved call interval structure. Focal whalesproduced 36% of their calls within 5 s of a call from a nonfocal animal, four times more calls than expectedby chance based upon a rotation randomization test. Consecutive calls produced by different individualsduring group-calling bouts matched call type more than expected by chance. Vocal exchanges ofstereotyped calls with type matching appear to be an important aspect of intragroup calling in killerwhales, although the function of this calling behaviour remains to be explored.14) Au, Whitlow W. L., John K. B. Ford, John K. Horne, Kelly A. Newman Allman. (2004). Echolocation signals of free-ranging killer whales (Orcinus orca) and modeling of foraging for chinook salmon (Oncorhynchus tshawytscha). The Journal of the Acoustical Society of America — February 2004 — Volume 115, Issue 2, pp. 901-909.
Abstract
Fish-eating "resident"-type killer whales (Orcinus orca) that frequent the coastal waters off northeastern Vancouver Island, Canada have a strong preference for chinook salmon (Oncorhynchus tshawytscha). The whales in this region often forage along steep cliffs that extend into the water, echolocating their prey. Echolocation signals of resident killer whales were measured with a four-hydrophone symmetrical star array and the signals were simultaneously digitized at a sample rate of 500 kHz using a lunch-box PC. A portable VCR recorded the images from an underwater camera located adjacent to the array center. Only signals emanating from close to the beam axis (1185 total) were chosen for a detailed analysis. Killer whales project very broadband echolocation signals (Q equal 0.9 to 1.4) that tend to have bimodal frequency structure. Ninety-seven percent of the signals had center frequencies between 45 and 80 kHz with bandwidths between 35 and 50 kHz. The peak-to-peak source level of the echolocation signals decreased as a function of the one-way transmission loss to the array. Source levels varied between 195 and 224 dB re:1 µPa. Using a model of target strength for chinook salmon, the echo levels from the echolocation signals are estimated for different horizontal ranges between a whale and a salmon. At a horizontal range of 100 m, the echo level should exceed an Orcinus hearing threshold at 50 kHz by over 29 dB and should be greater than sea state 4 noise by at least 9 dB. In moderately heavy rain conditions, the detection range will be reduced substantially and the echo level at a horizontal range of 40 m would be close to the level of the rain noise.15) Foote, Andrew D., Rachael M. Griffin, David Howitt, Lisa Larsson, Patrick J. O. Miller and A. Rus Hoelzel. (2006). Killer whales are capable of vocal learning. Biol. Lett. doi:10.1098/rsbl.2006.0525.
Abstract
The production learning of vocalizations by manipulation of the sound production organs to alter the physical structure of sound has been demonstrated in only a few mammals. In this natural experiment, we document the vocal behaviour of two juvenile killer whales, Orcinus orca, separated from their natal pods, which are the only cases of dispersal seen during the three decades of observation of their populations. We find mimicry of California sea lion (Zalophus californianus) barks, demonstrating the vocal production learning ability for one of the calves. We also find differences in call usage (compared to the natal pod) that may reflect the absence of a repertoire model from tutors or some unknown effect related to isolation or context.
Full paper here:
http://www.orcanetwork.org/nathist/vocallearnbiolett.pdf16) Oleson, Erin M., Sean M. Wiggins, and John A. Hildebrand (2006). Acoustic monitoring of resident, offshore, and transient killer whales off the Washington coast. J. Acoust. Soc. Am., Volume 120, Issue 5, p. 3015.
Abstract
Three acoustically distinct populations of killer whales representing each of the known ecotypes (resident, offshore, transient) were recorded in the Summer–Fall of 2004 off the southern Olympic Coast of Washington. Two high-frequency acoustic recording packages (HARPs) continuously recording at 80-kHz sample rate were deployed to assess the seasonal occurrence of vocal odontocetes in this region. From mid-July to early-October the population-specific discrete calls of killer whales were heard on 8 days and were classified to population by Volker Deecke (UBC) and John Ford (DFO-Canada) using an acoustic ID catalogue. West Coast Transient killer whales producing calls of the California dialect were heard on three occasions from August through October. Offshore killer whales were heard twice in August–September, and Northern Resident killer whales were heard once in August. Although Northern Resident killer whales have been extensively studied within Puget Sound and coastal British Columbia, they have been visually sighted only once off the northern Olympic Peninsula, making their detection at this offshore southerly location unique. Endangered Southern Resident killer whales were not heard at this site from July–October. Analysis of year-round data from a site further offshore is underway. [Funded by Chief of Naval Operations- N45.
<LINK>17) Simon, Malene, Fernando Ugarte, Magnus Wahlberg, and Lee A. Miller. (2006). Icelandic killer whales (Orcinus orca) use a pulsed call suitable for manipulating the schooling behaviour of herring (Culpea harengus). The International Journal of Animal Sound and its Recording, 2006, Vol. 16, pp. 57–74.
Abstract
Icelandic and Norwegian killer whales feed on herring, after debilitating them with underwater tail slaps. We analysed sound recordings of Icelandic and Norwegian killer whales engaged in feeding and other behaviour. We describe a pulsed call made by Icelandic killer whales shortly before underwater tail slaps, which had an atypical low frequency (average peak frequency: 683 ±131 Hz), long duration (3.0 ±1.1 s) and high intensity (source level 169-192 dB pp re 1 μPa @ 1 m). The low-frequency emphasis of this call was below the most sensitive hearing range of killer whales, suggesting that the call may not be optimal for interspecific communication. However, herring could easily perceive the killer whale call since the frequency content is similar to the resonant frequency of their swim bladder as well as to the most sensitive frequency band of hearing in this species. Previous studies have shown that sound may cause schooling herring to cluster. A high density of herring in a school would increase the effectiveness of the underwater tail slaps. We suggest that some Icelandic killer whales use this low-frequency call to herd herring into dense schools immediately before delivering an underwater tail slap, thereby increasing their foraging success.18) Filatova O.A., Fedutin I.D., Burdin A.M., Hoyt E. (2007). The structure of the discrete call repertoire of killer whales Orcinus orca from Southeast Kamchatka Bioacoustics. V 16(3): 261-280.
Abstract
The problem of categorization arises in any classification system because classes should be discrete while the characteristics of most natural objects and aspects of nature are more or less gradual. In systematics, this problem usually is solved by creating several levels of categories, such as class, order, family, genus and species. In the existing killer whale discrete call classification, only two levels occur - call type and call subtype. In this paper we describe structural categories at a broader level than call type in the discrete sounds of killer whales and compare these categories between and within vocal clans in a community of resident killer whales from Southeast Kamchatka, Russian Far East, and also with killer whales outside this community. We found four main classes of discrete calls in the repertoire of resident killer whales from Southeast Kamchatka. The calls of Southeast Kamchatka transient killer whales and Sakhalin killer whales do not fall into these classes. This suggests that the resident killer whale community from Southeast Kamchatka has some rules defining the structure of calls which are typical for this community. Consequently, all resident killer whales from Southeast Kamchatka can be said to share the same vocal tradition.
A pdf copy is available upon request from alazor@rambler.ru19) Morisaka, T., R. C. Connor (2007). Predation by killer whales (Orcinus orca) and the evolution of whistle loss and narrow-band high frequency clicks in odontocetes. Journal of Evolutionary Biology (OnlineEarly Articles). doi:10.1111/j.1420-9101.2007.01336.x.
Abstract
A disparate selection of toothed whales (Odontoceti) share striking features of their acoustic repertoires including the absence of whistles and high frequency but weak (low peak-to-peak source level) clicks that have a relatively long duration and a narrow bandwidth. The non-whistling, high frequency click species include members of the family Phocoenidae, members of one genus of delphinids, Cephalorhynchus, the pygmy sperm whale, Kogia breviceps, and apparently the sole member of the family Pontoporiidae. Our review supports the "acoustic crypsis" hypothesis that killer whale predation risk was the primary selective factor favouring an echolocation and communication system in cephalorhynchids, phocoenids and possibly Pontoporiidae and Kogiidae restricted to sounds that killer whales hear poorly or not at all (< 2 and > 100 kHz).20) Rehn, Nicola; Teichert, Stefanie; Thomsen, Frank. (2007). Structural and temporal emission patterns of variable pulsed calls in free-ranging killer whales (Orcinus orca). Behaviour, Volume 144, Number 3, 2007, pp. 307-329(23).
Abstract
Resident killer whales off Vancouver Island, British Columbia, produce variable burst pulsedcalls most commonly during close-range interactions such as socialising or social-travelling. Earlier studies indicated that variable calls are graded and can be arranged into a scale from low-frequency calls to high-frequency ones. These graded calls are often emitted in sequences, were call-classes of similar frequency follow one another more often than different classes. However, a detailed analysis of sequences was lacking to date. Therefore, our understanding of the function of variable calls during interactions among killer whales is rather limited. Simultaneous recordings of underwater vocalizations and behavioural observations from resident killer whales were collected off Vancouver Island, British Columbia during1996-2001. Socialising activities were divided into four categories: male-female, male-male, female-juvenile and juvenile-juvenile. Variable call sequences were analysed with RTS and SIGNAL acoustic-software. We found no positive correlation between group-size and number of used calls or the duration of sequences, indicating that only one or a few animals were involved in the production of each sequence. Furthermore, sequences were present in all four behaviour categories and the composition of the group had no influence on the duration of calls and used call-classes. One particular call class (V4) could be further separated into structurally distinct sub-classes. These sub-classes often formed rather stereotyped sequences. The results of our study indicate that sequences of variable calls emit broad motivational information that is not age or sex-related. Sequences of distinct sub-classes might encode more subtle information on emotional states during socialising. Therefore, variable calls might posses different functions, depending on the nature of the interaction. Thus, variable calls might be of great importance for close-range communication in wild killer whales.21) Simon, Malene, Magnus Wahlberg, and Lee A. Miller. (2007). Echolocation clicks from killer whales (Orcinus orca) feeding on herring (Clupea harengus) (L). J. Acoust. Soc. Am. 121 2, February 2007.
Abstract
Toothed whales. Order: Odontocetilisten for echoes from their intense, brief echolocation clicks to find prey. There have been many studies on the biosonar of captive odontocetes, but our understanding of how these animals use echolocation in the field is limited (Au, 2002). Killer whales (Orcinus orca) specialize in a large variety of prey species in different parts of the world. The acoustic properties of their biosonar signals have been described for the NE Pacific resident killer whales that feed mainly on salmon. Barrett-Lennard et al., 1996; Au et al., 2004. Comparing these data with those from other killer whale populations that feed on other prey species may reveal how the biosonar in this odontocete is adapted to different foraging situations and prey. Here we present the first acoustic analysis of fullbandwidth hydrophone array recordings of echolocation clicks from wild killer whales foraging on Atlantic herring Clupea harengus.22) Simon, Malene, Peter K. McGregor, and Fernando Ugarte (2007). The relationship between the acoustic behaviour and surface activity of killer whales (Orcinus orca) that feed on herring (Clupea harengus). Springer Berlin/Heidelberg Volume 10, Number 2 / November, 2007.
Abstract
We describe the acoustic behaviour of piscivorous killer whales in Norwegian and Icelandic waters. Whales were assigned to one of three activities (feeding, travelling or other), and sound recordings were made in their proximity with a single hydrophone and a digital audiotape (DAT) recorder. A quantitative analysis of the production of pulsed calls, whistles and echolocation clicks in the three activities revealed that there was a significant effect of activity on the production of these sound types. Both killer whales in Icelandic and Norwegian waters produced high rates of clicks and calls during feeding and low rates of click, calls and whistles during travelling. The differences can be used as acoustical markers and provides new possibilities for acoustic monitoring of killer whales in these areas. Based on the similarity between their prey choice, hunting strategies, phenotype and acoustic behaviour, we suggest that the killer whales in Icelandic and Norwegian waters belong to the same ecotype: Scandinavian herring-eating killer whales.
On this page, we provide abstracts (and in some cases the entire document) of numerous published scientific papers and reports.1) Bowers, C.A. and R.S. Henderson. (1972). PROJECT DEEP OPS: Deep Object Recovery with Pilot and Killer Whales. NUC TP 306. ABSTRACT »
2) Claridge, D., K. C. Balcomb. (1993). In Search of Marine Mammals.
ABSTRACT »
3) Cornell, L. (1993). Preliminary report to Jerye Mooney, Fund for the Animals, Re: Keiko-Reino Aventura, Mexico City, Mexico 7/08/93. ABSTRACT »
4) Newman, K., H. Markowitz. (1993). Echolocation by killer whales (Orcinus orca) while in pursuit of live fish.
ABSTRACT »
5) Small, R. and D. DeMaster. (1995). Survival of five species of captive marine mammals.
ABSTRACT »
6) Bossart, G. D., C. Cray, J. L. Solarzano, S. J. Decker, L. H. Cornell, N. H. Altman (1996). Cutaneous papillomaviral-like papillomatosis in a killer whale (Orcinus orca).
ABSTRACT »
7) McBain, et.al. (1998). Summary Report of Evaluation Panel Convened to Assess the Health of Keiko — January 28, 1998.
ABSTRACT »
Abstracts
1) Bowers, C.A. and R.S. Henderson. (1972). PROJECT DEEP OPS: Deep Object Recovery with Pilot and Killer Whales. NUC TP 306. Undersea Surveillance and Ocean Sciences Department, Naval Undersea Center, San Diego, CA. Unclassified, 86 pp.
Note: Describes in detail the US Navy program from 1968 to 1971 for two male killer whales (Ahab and Ishmael) which were captured in Puget Sound, WA and airlifted to Point Mugu, CA, and later to Kaneohe, HI. Both killer whales were maintained at NUC Hawaii in fenced ocean pens, "...with low maintenance costs and excellent animal health." By September 1970, both whales had attained "open ocean reliability," wherein they would accompany a vessel out to sea an average of five times per week for a round trip distance of 10-12 nautical miles, typically swimming alongside the vessel at speeds of 6-7 knots. Ishmael on 19 February 1971 did not respond to his underwater recall signal and apparently swam away. On 8 June 1971, Ahab went on a 24 hour excursion ranging over 50 nautical miles in a northwesterly direction along the Oahu coast, and no further sea trials were conducted with him. Ahab died in 1974 at an estimated age of 15-16.
2) Claridge, D., K. C. Balcomb. (1993). In Search of Marine Mammals. Bahamas Naturalist, Vol 7:1 p. 11-17.
Note: In addition to a general survey of marine mammals of the northern Bahamas, this article discusses Bahama Mama, an adult female bottlenose dolphin inadvertently released to her assumed native habitat in 1992 after at least seventeen years of captivity. No official followup occurred, however this dolphin was positively photo-identified up to eight months after release in the company of wild dolphins in the Bahamas. This reintroduction, with no preparation, although not an example for future releases, gives reason for confidence in the species' ability to readapt to natural conditions.
3) Cornell, L. (1993). Preliminary report to Jerye Mooney, Fund for the Animals, Re: Keiko-Reino Aventura, Mexico City, Mexico 7/08/93.
Quote: "This male orca, now about 10 to 12 years of age has been examined by several veterinarians in the past year or so to determine his health status and to establish his value for purchase by their aquariums and marine zoological parks. Keiko has been held in a small pool for these past years, one which could not meet even the meager standards and guidelines of the United States Department of Agriculture (USDA).
"The question now is how long can the whale survive in this facility and where will he go if removed from Mexico City?
"To their credit the owners and curatorial and training staff at Reino Aventura realize the animal is in improper conditions and have repeatedly asked other zoological facilities for their help in relocating him as they have not the money to build him new pools and life support systems as would be needed to secure his future. Until now they have repeatedly been refused in their attempts to sell or relocate him because he suffers from skin conditions which appear to be viral pappilomatous masses at the axillary area on both pectoral fins and another similar lesion on his tail stock anterior to his flukes. If these lesions are indeed viral, and his history would indicate they might be, his contact with other orcas and perhaps other animals of any kind could place those animals in jeopardy of exposure and possibly infection by the same virus(s) until he has been cleared up, assuming this is a virus which is not already endemic in these animals and which is obvious in Keiko because of his environment.
"The results of the clinical blood values and the tissue samples will not be available to us for some days, so for this preliminary report we will evaluate the animal solely on the basis of his history and our examinations, both behaviorally and physically.
"Keiko is, as we have pointed out, a male orca captured in the North Atlantic by Icelandic fishermen in about November of 1983. Judging by his alleged capture size he was about a yearling at that time plus or minus a year.
"After his capture, he was placed in a facility in Canada along with several other orcas and maintained in training as a future show animal until his sale to Reino Aventura in 1985. He is remarkably well adapted to his situation in that he is completely docile, well trained, under the circumstances and appears to be very well liked by the staff. And he appears to like the staffs of trainers as well. He is very responsive to them even when he is not hungry. He is approximately 20 feet in length and weighs only about 5000 pounds, considerably small of stature for an orca of his age and sexual maturity. He is unusually alert and is accompanied in his small shallow pool by a male bottlenosed dolphin which has not yet shown signs of skin diseases despite his continued daily environmental and physical contact with Keiko. Keiko eats only a small amount -120 pounds of food each day- due to the excessively high water temperatures in his pool (average 75-80 plus degrees fahrenheit). These excess temperatures-killer whales are usually found in water temperatures below 60 degrees F-are also responsible for his thin stature as there is no need for extra blubber to maintain warmth in this heat, instead his problem is how to stay cool as is evidenced by the daily lethargy which overtakes the animal as each day progresses in warmer weather. His teeth are worn down from rubbing on hard surfaces and are about 50% to the gum line at the anterior third of his jaws both top and bottom.
"The most significant findings of the physical examination other than his small size and teeth are the proliferative skin lesions at his axillary region and tail stock and the overall poor condition of his skin generally which is solely the result of the improper mix of salt in his pool. The lesions are very rough and bumpy in texture and are spreading again, at this time despite the extensive previous treatments with autogenous vaccines made from tissues removed from the whale. He has also been treated with large doses of immune response stimulants to no great permanent avail.
"According to the records shown to me, Dr.S Solorzano remarked at the small skin lesions at the base of both pectoral fins shortly after the whale's arrival mexico in 1985, this would indicate a chronicity of some determination. That there have been several extensive and time consuming attempts to "cure" Keiko indicate there is not likely to be an answer to his problem in his present situation and facility. Thus, if the whale is to be saved, rehabilitated and released, his facility must be rebuilt to modern, state of the art conditions which is not likely due to the owners' lack of funding, or, he must be moved somewhere with high quality cool sea water. This means some effort on the part of those interested parties. In the past several people have seen or reported lesions similar to this in orcas in captive environments. All of these have been in man made sea water save one. All facilities involved were of questionable water quality at the time the lesions were seen. All except this one have at this writing been cleared up, apparently spontaneously, after the water quality problems involved were addressed. (I would not be surprised to have, some day, a report of these lesions naturally occurring in young wild killer whales as we have already seen with walrus and sealions).
"Thus, to save Keiko one must first rebuild his existing pools or locate a facility willing to take the whale which has cool natural sea water as its source. The animal, once in such a facility, will likely improve its skin condition spontaneously, in time, with the retrieval in its body of the natural trace elements he now lacks and he will also gain weight accordingly, when no longer stressed and challenged by the chronic heat loss problems he now faces.
"There is no doubt that whales and dolphins can successfully be released to the wild. Many people have been involved in such releases in the past, some on purpose and some accidentally.
— Lanny H. Cornell, DVM
####
Addendum to Keiko summary:
"The histopathology report done by routine histology is non commital about infection either by bacteria or viruses. The pathologist reports he believes the skin reaction to be the result of continued insult by chemical exposure, and states he has seen this previously in whales but does not give particulars
"The electronmicroscopy report has been slow coming in as they usually are. The pathologist here reports he sees no viruses but does see numerous bacterial colonies in the tissues submitted. The tissues were taken by scalpel from the most active parts of the lesion nearest the junction with normal skin tissue visually. This is normally where one would see the invasive organism(s) and would be the best place to judge the kind of confection present. Thus, one would have to believe we are dealing with a contact dermatitis here, caused by some external source and secondarily invaded by bacteria. If this were primarily a virus or a bacterial infection one would find the causative organisms all over the wounds instead of just in some areas as we see here.
"Conclusions: It would appear we are dealing with an iatrogenic disease. Probably this problem is the result of chronic water quality and/or environmental problems in the animal's water and could be corrected on site through the expenditure of a proper water filtration and treatment plant, or more likely, since they have had the animal there for some years and done nothing to change their water system, by moving the animal to a proper location with viable water quality for killer whales.4) Newman, K., H. Markowitz. (1993). Echolocation by killer whales (Orcinus orca) while in pursuit of live fish. Abstract from Marine Mammal Conference.
Abstract
Echolocation use by cetaceans has been postulated to be functional in a natural environment, but might not be used as frequently in a captive setting where the water is clear and the whales are handfed. The object of this study was to see if captive Orcinus orca used echolocation when presented with live fish. We fed live coho salmon (Onchorhynchus klautch) to two captive killer whales at Marine World Africa, U.S.A., Vallejo, CA. The experiment was videotaped and recorded on a high frequency Racal 4D store four-track tape machine at 30 inches per second. A hydrophone array, consisting of a B&K 8104, a B&K 8105 and a Magnavox, was used to receive the sounds. Recordings of echolocation clicks were slowed down and analyzed with a Kay Elemetrics DSP 5500 Sonagraph and a MacAdios sound analysis program.
Results of this study demonstrate that captive killer whales will pursue, capture, and eat live fish. The whales in this study used echolocation while in pursuit of fish, as well as at other times. Preliminary analyses of echolocation clicks reveal spectral energy up to 80 kilohertz.5) Small, R. and D. DeMaster. (1995). Survival of five species of captive marine mammals. Marine Mammal Science, Vol. 11:2, p. 209-226.
Abstract
Survival in captivity was calculated for 1707 bottlenose dolphins (BD), 72 killer whales (KW), 73 white whales (WW), 3,090 California sea lions (CSL), and 47 Steller sea lions(SSL) based on data in the Marine Mammal Inventory Report (MMIR) of the NMFS. Mean annual survival rates (ASRs) between 1988 and 1992 were 0.951, 0.937, and 0.954 for BD, KW, and WW, respectively, and 0.952 and 0.969 for CSL and SSL, respectively. These estimates represent significant increases in survival for both BD and CSL over the last 5 yr. Using all of the MMIR data (1940-1992), the ASR of BD calves (<1yr of age) was significantly less than the ASR of non-calves (0.666 vs 0.946, P,<0.0001). Survival of captive-born CSL was significantly higher than those born in the wild (0.962 vs 0.945, P = 0.003), but the difference was not significantly different for BD (0.948 vs 0.944, P = 0.60). For non-calf BD and KW, captive animals survived at a slightly lower rate (BD 0.944 vs 0.961, P = 0.07; KW 0.938 vs 0.976 P < 0.001) than animals in the wild (BD: Wells and Scott 1990, KW: Olesiuk et. al. 1990). Survival of captive non-pup SSL was slightly higher (0.968 vs 0.930) than animals in the wild (York 1994, life table analyses). Survival rates were significantly different among institutions for BD calves and non-calves, CSL pups and non-pups, and SSL non-pups.
Quote: Survival of the wild population Olesiuk et al. studied, based on approximately 250 non-calves, was significantly higher than our estimates for non-calf captive killer whales (0.976 vs. 0.938, P<0.001).6) Bossart, G. D., C. Cray, J. L. Solarzano, S. J. Decker, L. H. Cornell, N. H. Altman (1996). Cutaneous papillomaviral-like papillomatosis in a killer whale (Orcinus orca). Marine Mammal Science, Vol. 12:2, p. 274-281.
Quote: "In this report, we document the first case of cutaneous papillomaviral-like papillomatosis in a killer whale. An approximately 10-yr-old male killer whale of Icelandic origin ("Keiko") developed bilateral axillary skin lesions soon after its arrival at a Mexico City oceanarium in 1985." ..."Studies are underway to characterize this presumptive viral disease and to address the potential immunological aspects of its pathogenesis. These studies include evaluation and characterization of the physiological and immunological status of the whale, isolation and characterization of the papilloma-associated virus, and subsequently the design and implementation of potential treatment regimens."
Note: This report is noteworthy because it mentions the word "virus" in the title ("papillovaviral-like") and throughout the paper, and it states that this virus is the "first case" found in a killer whale, strongly suggesting that Keiko was infected with a virus foreign to wild populations, without quite stating clearly that Keiko actually carried any virus. At the time the paper was written many spokespeople for the marine park industry were stating publicly that Keiko should never be released because he carried a contagious virus that could infect wild populations. In 1993, prior to this report, one of its authors, (Cornell), had written a report stating that Keiko's skin problems were the result of environmental stresses and not related to any virus. In 1998, after Bossart, et al.'s report was published, a group of six veterinarians and specialists appointed by the USDA examined Keiko and found him negative for 48 suspected viruses. (See USDA report: (LINK) Bossart, et al.'s frightening viral theory was apparently incorrect.)7) McBain, et.al. (1998). Summary Report of Evaluation Panel Convened to Assess the Health of Keiko-January 28, 1998.
Panel Members:
Dr. James McBain, Sea World, Inc.
Dr. Al Smith, Oregon State University
Dr. Jeffery Stott, University of California at Davis
Dr. Joseph Geraci, National Aquarium in Baltimore
Mr. Bud Krames, Dolphin Quest
Dr. Barbara Kohn, USDA, APHIS, AC - Facilitator
Other Contributors:
Dr. Isis Johnson, USDA, APHIS, AC
Dr. Randy Ridenour, USDA, APHIS, AC
This independent evaluation was done with the full backing and support of the Free Willy Keiko Foundation. Foundation liaisons were Mr. Joseph Gaskins and Mr. Robert Ratliffe.
The Panel wishes to thank the staff at the Free Willy Keiko Foundation and the Oregon Coast Aquarium for their cooperation with this evaluation. The Panel was welcomed with open arms. We wish to thank Dr. Lanny Cornell for his cooperation.
Keiko, a male killer whale, Orcinus orca, was transported to the United States and housed at a newly built facility within the Oregon Coast Aquarium (OCA) in January 1 1996. Since that time the animal has been under the care of the OCA and the Free Willy Keiko Foundation (FWKF). Due to the history and popularity of the whale, his health and well being have been subjected to a high degree of public and media scrutiny. In August 1997, after a change in personnel handling the day-to-day care of Keiko and after conflicting reports of his health status, APHIS was asked to facilitate the formation of an independent panel of marine mammal experts who would assess the current health status of Keiko. This panel was formed in October 1997 with the cooperation of the FWKF. The panel included veterinary experts, including a virologist and immunologist, as well as two veterinary clinicians, a behaviorist, and an APHIS representative as a facilitator. The animal was evaluated by the panel members during December 1997 and January 1998.
Keiko is an approximately 18 year old killer whale whose living condition and health concerns came to light when he was chosen to star in the movie, Free Willy. At that time, Keiko resided in a facility in Mexico (Reino Aventura), in which the pool was small and water quality was poor including inappropriate temperature. Keiko has had no conspecific companionship since he resided in Canada, but he did have dolphin companionship at Reino Aventura. After several years of negotiations and attempts to move Keiko to a more appropriate facility, arrangements were made to move him to the OCA facility, which was leased by the FWKF. Keiko's health has been a constant concern with the most visible problem being a viral (assumed) skin condition which was visible even during the filming of the movie. The skin condition did appear to improve after the transfer to the Oregon facility with its improved water quality.
Methodology:
Keiko was examined by a marine mammal veterinarian and samples were obtained for generally accepted routine medical testing, including a complete blood count and chemistry profile. ...
Results and Evaluation:
To gain the best picture of the health status of any animal, one should monitor appropriate parameters over time, using repeated testing. This panel was formed to evaluate a "snapshot" of Keiko's medical and behavioral condition. To provide the best evaluation under these circumstances, the panel relied on the medical and behavioral records of the animal, as well as examinations and testing done in November 1997 through January 1998.
Based on clinical pathology results, there is a high probability that Keiko developed a hepatopathy beginning in June 1997. The primary manifestation of this event was a significantly elevated liver enzyme which did not return to normal until December 1997. Keiko was treated with an antifungal drug for a suspected lung infection during the latter period of enzyme elevation. This complicated interpretation of the enzyme values since the antifungal agent used is known to occasionally produce a transient elevation in liver enzymes, which may persist over a long period of time. The return of the liver enzymes to normal levels indicated that, in the very least, the condition is in remission.
During his residency in Oregon, Keiko experienced a tooth fracture which later required extraction. There have also been multiple episodes of hematuria. Recent urinalyses demonstrate that hematuria is no longer present. Dr. Lanny Cornell, attending veterinarian for the FWKF, indicated that Keiko has a penile lesion which was the likely source of blood in the urine. The lesion has healed. Observers have reported the occurrence of behaviors described as "cramping" and "twitching." The Panel's veterinary clinicians have not seen these behaviors, nor is any video available. As a result their cause and significance cannot be determined. The behaviors have been noted since Keiko's arrival in Oregon, and to date no disease condition has been associated with them.
In late December 1997, a small skin lesion on the leading edge of the right pectoral flipper was observed. It was approximately 1" in diameter and visually appeared to be a papilloma. The lesion was biopsied, and although cytopathology was evident on the first but not the second and third growth passages, histology and initial cell culture tend to support the growth being the result of a papilloma (wart) virus. This condition is known to occur in wild and captive whales and is not considered a health challenge to Keiko. Other skin lesions which have been observed on Keiko have been examined and biopsied when appropriate (fresh lesions). Although such lesions resembled possible viral skin lesions, no specific viral etiology has been identified.
Blood (serum and buffy coats) samples were subjected to rigorous viral isolation and/or viral antigen testing for 49 antigens, including 33 serotypes of caliciviruses (oceanic and nonoceanic), marine species virus isolates of herpes virus, rotavirus-like virus, entorvirus-like virus, retrovirus-like virus, and three adenoviruses, as well as other miscellaneous viruses, including morbillivrius, parvovirus, and human hepatitis virus, canine adanovirus, and LDH virus. Antibody testing for 48 of the 49 viruses is complete at this time. Antibody tests were negative, and there were no viruses isolated (emphasis added).
Samples collected to evaluate the immunological status of Keiko revealed that he has a low circulating B-lymphocyte count and a slightly elevated total immunogloubulin level. Immunealactrophoresis of the serum proteins indicated that there may be a missing isotype of IgG. However, the significance of this finding is unknown. T-lymphocyte function appears to be adequate in this animal.
Behavioral observations of Keiko indicate a variation in his behavior patterns. In December 1997, he appeared "frustrated" and not content. In January 1998, Keiko appeared calm, if bored. Both observers felt Keiko might be feeling the effects of not having any control over his environment. However, no stereotypic or destructive (typical neurotic behaviors such as head butting or staring into the walls) swimming or other behaviors were observed.
Keiko related well to his trainers, but it was felt that the response thresholds for the training sessions were low, and Keiko's response to stimuli, though not normal, was slow. The primary reinforcement tool preferred by Keiko was tactile stimulation after a session. He does not appear to be food driven in his interactions. Keiko was provided enrichment devices and interacted with them randomly, especially enjoying the high-powered water jets used for environmental enrichment.
Overall, Keiko appeared to have no behavioral problems that adversely affected his health. Several panel members expressed concern that Keiko, may not have a great deal of stamina and that even small body movements created visible movement of skin. This apparent flaccidity of Keiko's body could indicate insufficient muscle mass, lack of muscle tone, or recent changes in weight. Keiko continues to gain weight and grown since his move to Oregon.
APHIS inspections, conducted by a 2-person team, showed the facility in compliance with the AWA regulations and standards in July 1997 and December 1997.
Summary and Recommendations
There is no current indication that Keiko is ill. He showed no clinical pathological evidence of chronic deep-seated infection during his residence in Oregon. Immunological test results are apparently within known normal parameters, and there was no evidence of recent viral challenges to 48 different viruses. Keiko appeared to be exhibiting no abnormal behavior patterns. At the time of the study, Keiko was recovering from an illness (probable hepatopathy) of several months' duration. The only known chronic condition in evidence is probable papillomatosis. This snapshot analysis must be viewed as that-a look at one point in time. Questions and concerns about Keiko's long-term health status and options for his future need to be studied over a much longer period of time. Given Keiko's past health history and ongoing concerns and scrutiny of his health, the panel makes the following recommendations:
1. Continue monitoring and follow-up testing to further establish a baseline for Keiko's medical results and to provide reliable scientific documentation of his overall health picture.
2. Given Keiko's past health history and potential future plans, a written line of authority must be established, which assures that the husbandry and medical programs are integrated in a way which places a single person in ultimate authority. This will required commitment, cooperation, and communication between the husbandry staff, water quality engineers and operators, and veterinary care personnel.
3. Ancillary to "2" above, complete and useful medical, training, and feeding records are necessary for any future evaluation of Keiko's health. These records should be well organized and readable and provide an accurate picture of all tests, treatments and responses.
4. Keiko appears to have flaccidity in his body, evidenced by highly movable skin. This could bean insufficient muscle mass or lack of muscle tone. Keiko should continue a program to improve his body tone and endurance. Such a program should include, at least, a program of regular, increasing exercise, and monitoring of weight and appetite.
5. Although Keiko's dependence on human interaction may facilitate handling by the trainers, killer whales are social creatures and should be afforded interactions with same or other compatible marine species. Section 3.109 of the AWA regulations and standards requires such access. A companion animal is recommended and should be a compatible cetacean or, if necessary, pinniped species.
6. Any decision on the rehabilitation of Keiko should be made in concert with an ongoing, long-term health study and evaluation. An expert panel assembled by the responsible parties is recommended to oversee this task.
Note: This is reprinted in full because it clears up the confusion created by the claims that Keiko ever had a contagious foreign pathogen, as suggested by Bossart, et al., and because this panel provides a model process for examining any potential candidate for release or retirement in natural habitats.
On this page, we provide abstracts (and in some cases the entire document) of numerous published scientific papers and reports.1) Olesiuk, P.F., M.A. Bigg and G.M. Ellis. (1990). Life history and population dynamics of resident killer whales (Orcinus orca) in the coastal waters of British Columbia and Washington State.
ABSTRACT »
2) Hoelzel, A. Rus. (1991). Killer whale predation on marine mammals at Punta Norte, Argentina; food sharing, provisioning and foraging strategy.
ABSTRACT »
3) Ford, J.K.B., G.M. Ellis, L.G. Barrett-Lennard, A.B. Morton, R.S. Palm, and K.C. Balcomb III. (1999). Dietary specialization in two sympatric populations of killer whales (Orcinus orca) in coastal British Columbia and adjacent waters.
ABSTRACT »
4) Smith, J.C., K.M. Balcomb-Bartok, K.M., R.W. Osborne, R.W., and K.C. Balcomb III. (1999) The L25 subpod of killer whales (Orcinus orca) in Dyes Inlet, Washington (1997).
ABSTRACT »
5) Baird, Robin W. and Hal Whitehead. (2000). Social organization of mammal-eating killer whales: group stability and dispersal patterns.
ABSTRACT »
6) Ross, Peter S.; G. M. Ellis; M. G. Ikonomou; L. G. Barrett-Lennard; and R. F. Addison. (2000). High PCB concentrations in free-ranging Pacific killer whales, Orcinus orca: Effect of age, sex and dietary preference.
ABSTRACT »
7) Saulitis, Eva, Lance Barrett-Lennard, Kathy Heise, Graeme Ellis. (2000). Foraging strategies of sympatric killer whale (Orcinus orca) populations in Prince William Sound, Alaska.
ABSTRACT »
8) Scheel, D.; Craig O. Matkin and Eva Saulitis. (2001). Distribution of killer whale (Orcinus orca) pods in Prince William Sound, Alaska 1984-1996.
ABSTRACT »
9) Hoelzel, A. Rus, Ada Natoli, Marilyn E. Dahlheim, Carlos Olavarria, Robin W. Baird and Nancy A. Black (2002). Low worldwide genetic diversity in the killer whale (Orcinus orca): implications for demographic history.
ABSTRACT »
10) Dr. Peter S. Ross. (2002) Killer whales as sentinels of marine ecosystem contamination.
ABSTRACT »
11) Williams, Rob, Andrew W. Trites, and David E. Bain. (2002). Behavioural responses of killer whales (Orcinus orca) to whale-watching boats: opportunistic observations and experimental approaches.
ABSTRACT »
12) Pitman, Robert L. (2003). Good whale hunting: two tantalizing Russian reports take the author on a quest to the Antarctic, in search of two previously unrecognized kinds of killer whale.
ABSTRACT »
13) Marino, Lori; Chet C. Sherwood, Bradley N. Delman, Cheuk Y. Tang, Thomas P. Naidich, Patrick R. Hof. Neuroanatomy of the killer whale (Orcinus orca) from magnetic resonance images.
ABSTRACT »
14) Rayne, Sierra, Michael G. Ikonomou, Peter S. Ross, Graeme M. Ellis, Lance G. Barrett-Lennard. (2004). PBDEs, PBBs, and PCNs in Three Communities of Free-Ranging Killer Whales (Orcinus orca) from the Northeastern Pacific Ocean.
ABSTRACT »
15) Balcomb, K.C., Parsons, K.M., Wade, P.R. (draft, unpub. 2005). Conservation of the Southern Resident killer whale poulation: a preliminary look at dynamic survival rates and environmental covariates. (Dynamic Survival Rates and Environmental Covariates).
Link coming soon »
16) Ford, John K.B., Graeme M. Ellis. (2005). Prey selection and food sharing by fish-eating ‘resident’ killer whales (Orcinus orca) in British-Columbia.
ABSTRACT »
17) Ford, John K.B., Graeme M. Ellis. (2005). Selective foraging by fish-eating killer whales Orcinus orca in British Columbia.
ABSTRACT »
18) Ford, J.K.B., G.M. Ellis, P.F. Olesiuk. (2005). Linking Prey and Population Dynamics: did food limitation cause recent declines of 'resident' killer whales (Orcinus orca) in British Columbia?
ABSTACT »
19) Baird, R.W., D.J. McSweeney, C. Bane, J. Barlow, D.R. Salden, L.K. Antoine, R.G. LeDuc and D.L. Webster. (2006). Killer whales in Hawaiian waters: information on population identity and feeding habits.
ABSTRACT »
20) Morin, Phillip A. Richard G. LeDuc, Kelly M. Robertson, Nicole M. Hedrick, William F. Perrin, Michael Etnier, Paul Wade, Barbara L. Taylor. (2006). Genetic analysis of killer whale (Orcinus Orca) historical bone and tooth samples to identify western U.S. ecotypes.
ABSTRACT »
21) Nousek, Anna E., Peter J.B. Slater, Chao Wang, Patrick J.O. Miller. (2006). The influence of social affiliation on individual vocal signatures of northern resident killer whales (Orcinus orca).
ABSTRACT »
22) Zerbini, Alexandre N., Janice M. Waite, John W. Durban, Rick LeDuc, Marilyn E. Dahlheim and Paul R. Wade. (2006). Estimating abundance of killer whales in the nearshore waters of the Gulf of Alaska and Aleutian Islands using line-transect sampling.
ABSTRACT »
23) Burdin, Alexander M., Erich Hoyt, Olga A. Filatova, Tatyana Ivkovich, Karina Tarasyan and Hal Sato. (2007). Status of Killer Whales (Orcinus orca) in Eastern Kamchatka (Russian Far East) Based on Photo-Identification and Acoustic Studies.
ABSTRACT »
24) Hickie, Brendan E., Peter S. Ross, Robie W. Macdonald, and John K. B. Ford. (2007). Killer Whales (Orcinus orca) Face Protracted Health Risks Associated with Lifetime Exposure to PCBs.
ABSTRACT »
25) Krahn, Margaret M., M. Bradley Hanson, Robin W. Baird, Richard H. Boyer, Douglas G. Burrows, Candice K. Emmons, John K.B. Ford, Linda L. Jones, Dawn P. Noren, Peter S. Ross, Gregory S. Schorr, Tracy K. Collier. (2007). Persistent organic pollutants and stable isotopes in biopsy samples (2004/2006) from Southern Resident killer whales.
ABSTRACT »
26) Pitman, Robert L., Wayne L. Perryman, Don Leroi, and Erik Eilers. (2007) A dwarf form of killer whale in Antarctica.
ABSTRACT »
27) Steiger, G.H., J. Calambokidis, J.M. Straley, L.M. Herman, S. Cerchio, D.R. Salden, J. Urbán-R, J.K. Jacobsen, O. von Ziegesar, K.C. Balcomb, C.M. Gabriele, M.E. Dahlheim, S. Uchida, J.K.B. Ford, P. Ladron de Guevara-P, M. Yamaguchi and J. Barlow. (2008). Geographic variation in killer whale attacks on humpback whales in the North Pacific: implications for predation pressure.
ABSTRACT »
28) Matkin, C.O., E.L. Saulitas, G.M. Ellis, P. Olesiuk, and S.D. Rice. (2008). Ongoing population-level impacts on killer whales Orcinus orca following the Exxon Valdez' oil spill in Prince William Sound, Alaska.
ABSTRACT »
29) K.M. Parsons, K.C. Balcomb, J.K.B. Ford, J.W. Durban. (2009).The social dynamics of southern resident killer whales and conservation implications for this endangered population
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Abstracts
1) Olesiuk, P.F., M.A. Bigg and G.M. Ellis (Dept. of Fisheries and Oceans, Pacific Biological Station, Nanaimo, B.C., Canada V9R 5K6). (1990). Life history and population dynamics of resident killer whales (Orcinus orca) in the coastal waters of British Columbia and Washington State. In: P.S. Hammond, S.A. Mizroch and G.P. Donovan (eds.): Individual recognition of cetaceans: Use of photo-identification and other techniques to estimate population parameters. Special Report #12, International Whaling Commission, Cambridge, p. 209-243.
Abstract
Life history parameters are derived for the resident form of killer whale in the coastal waters of British Columbia and Washington State based on the demographic changes observed in two communities (closed to immigration and emigration) that were monitored between 1973-4 and 1987. Females have a mean life expectancy of 50.2 years, typically give birth to their first viable calf at 14.9 years of age, produce an average of 5.35 viable calves over a 25.2 year reproductive lifespan and have a maximum longevity ofabout 80-90 years. Calving is diffusely seasonal with most births occurring in October-March. Neonate mortality is approximately 43%. The estimated proportion of mature females pregnant varies from 0.274 in April to 0.411 in September. Males have a mean life expectancy of 29.2 years, typically attain sexual maturity at 15.0 years and physical maturity at 21.0 years of age, and have a maximum longevity of about 50-60 years. Mortality curves are U-shaped for both females and males, but the curve is narrower for males. There is no evidence of density dependence in the life history parameters as a result of cropping prior to the start of the study or as the populations increased during the study.
The derived life history parameters are used to develop a sex-and age-specific matrix population model and to calculate life tables. The model accurately emulates the demographic changes observed during the study. Population projections indicate that both communities represent stable populations below their carrying capacity. These populations had a finite annual rate of increase of 2.92% and were composed of 50% juveniles, 19% mature males, 21% reproductive females and 10% post-reproductive females. Discrepancies between the sex- and age-structure of the study populations and those of a stable population can be largely attributed to the selective cropping of pods prior to the start of the study. (...)
Note: 261 Pacific Northwest killer whales were alive in 1987 in two resident communities. A community comprises individuals that share a common range and associate with one another; a pod is a group of individuals within a community that travels together the majority of the time; a subpod is a group of individuals that temporarily fragments from its pod to travel separately; an intra-pod group consists of a cohesive group of individuals within a subpod that always travels in close proximity. The genealogical trees indicate that intra-pod groups are matrilines. A matrilineal group typically comprises 2-4 generations. Pod-specific dialects suggest that related pods associate randomly. The lack of dispersal of the resident form of killer whale from their natal groups appears to be unique among mammalian social systems. This species has the potential to have developed many local races over its cosmopolitan range, with each race having unique social and behavioral characteristics.2) Hoelzel, A. Rus. (1991). Killer whale predation on marine mammals at Punta Norte, Argentina; food sharing, provisioning and foraging strategy. Proc. Royal Soc. B 269: 1467-1475.
Abstract
The social dynamics of killer whales (Orcinus orca) that hunt marine mammals are apparently highly flexible, though strong individual associations do exist. The killer whales at Punta Norte offer an unusually detailed view of association patterns and foraging behaviour, and suggest a pattern of behaviour that optimizes hunting efficiency with exception only to strong associations between some individuals and the provisioning and training of offspring. The main points from this paper are as follows: First, hunting effort was concentrated where the capture rate was greatest. All pods selectively attacked the prey type for which they had the highest capture rate. The amount of southern sea lion prey captured was approximately equal to the estimated minimum energetic requirement for killer whales based on weight. Secondly, one whale in each pod did the majority of the hunting, and then provisioned the others in the pod. It was clear on numerous occasions that food was shared. A review of reported incidences of killer wales taking marine mammal prey suggests that it is common for a subset of the individuals in a pod to hunt. These results are discussed in the context of the evolution of foraging behaviour.3) Ford, J.K.B., G.M. Ellis, L.G. Barrett-Lennard, A.B. Morton, R.S. Palm, and K.C. Balcomb III. (1999). Dietary specialization in two sympatric populations of killer whales (Orcinus orca) in coastal British Columbia and adjacent waters. Canadian Journal of Zoology, Vol. 76, p. 1456-1471.
Abstract
Two forms of killer whale (Orcinus orca), resident and transient, occur sympatrically in coastal waters of British Columbia, Washington State, and southeastern Alaska. The two forms do not mix, and differ in seasonal distribution, social structure, and behaviour. These distinctions have been attributed to apparent differences in diet, although no comprehensive comparative analysis of the diets of the two forms has been undertaken. Here we present such an analysis, based on field observations of predation and on the stomach contents of stranded killer whales collected over a 20-year period. In total, 22 species of fish and 1 species of squid were documented in the diet of resident-type killer whales; 12 of these are previously unrecorded as prey of O. orca. Despite the diversity of fish species taken, resident whales have a clear preference for salmon prey. In field observations of feeding, 96% of fish taken were salmonids. Six species of salmonids were identified from prey fragments, with chinook salmon (Oncorhynchus tshawytscha) being the most common. The stomach contents of stranded residents also indicated a preference for chinook salmon. On rare occasions, resident whales were seen to harass marine mammals, but no kills were confirmed and no mammalian remains were found in the stomachs of stranded residents.
Transient killer whales were observed to prey only on pinnipeds, cetaceans, and seabirds. Six mammal species were taken, with over half of observed attacks involving harbour seals (Phoca vitulina). Seabirds do not appear to represent a significant prey resource. This study thus reveals the existence of strikingly divergent prey preferences of resident and transient killer whales, which are reflected in distinctive foraging strategies and related sociobiological traits of these sympatric populations.4) Smith, J.C., K.M. Balcomb-Bartok, R.W. Osborne, and K.C. Balcomb III. The L25 subpod of killer whales (Orcinus orca) in Dyes Inlet, Washington (1997).
Abstract
On October 21, 1997, 19 killer whales (Orcinus orca) from the Southern Resident subpod L25 were reported in Dyes Inlet near Bremerton, Washington, USA. The whales had likely followed a Chum Salmon (Oncorhynchus keta) run to Chico Creek, one of the last well preserved fall spawning streams in Puget Sound. Members of The Center For Whale Research arrived in the following days with hydrophones, video and behavior logs to observe the animals.
The whales stayed for a total of 30 days, during which time thousands of people arrived and took the opportunity to view the killer whales. All nineteen whales left on a rainy Wednesday afternoon, escorted through the Port Washington Narrows and under the Warren Avenue bridge by The Friday Harbor Whale Museums' Soundwatch vessel as well as Echo, an inflatable research vessel from the National Marine Mammal Labs.
Data was collected consistently from November 1 through November 19, 1997, highlighting the predator-prey relationship of the killer whales and the chum salmon. We use this data as well as other cases to illustrate the possibility of entrapment within the Inlet. Because of the rare nature of incidences such as this, we discuss whale/human interactions and give recommendations on boater management should a similar situation happen again.5) Baird, Robin W. and Hal Whitehead. (2000). Social organization of mammal-eating killer whales: group stability and dispersal patterns. Canadian Journal of Zoology 78:2096-2105.
Abstract
The social organization of mammal-eating "transient" killer whales (Orcinus orca) was studied off southern Vancouver Island from 1985 through 1996. Strong and long-term associations exist between individual transients, so sets of individuals with consistently high association levels, termed pods, can be delineated. Pods consist of individuals of mixed ages and sexes, and typically contain an adult female and one or two offspring (averaging 2.4 individuals). The mother-offspring bond remains strong into adulthood for some male (and less often for female) offspring. Other males disperse from their maternal pod and appear to become "roving" males, spending some of their time alone, and occasionally associating with groups that contain potentially reproductive females. These males appear to have no strong or long-term relationships with any individuals, and adult male - adult male associations occur significantly less often than expected by chance. Females that disperse from their natal pod appear to be gregarious (having high average association rates) but socially mobile (having low maximum association rates). Differences in social organization from the sympatric fish-eating "resident" killer whales (where no dispersal of either sex occurs) likely relate to differences in foraging ecology. Transient killer whales maximize per capita energy intake by foraging in groups of three individuals, whereas no such relationship has been documented for resident killer whales.6) Ross, Peter S.; G. M. Ellis; M. G. Ikonomou; L. G. Barrett-Lennard; and R. F. Addison. (2000). High PCB concentrations in free-ranging Pacific killer whales, Orcinus orca: Effect of age, sex and dietary preference. Marine Pollution Bulletin 40:504-515.
Abstract
Blubber biopsy samples were obtained for contaminant analysis from two discrete populations of killer whales (Orcinus orca) which frequent the coastal waters of British Columbia, Canada. Detailed life history information for the fish-eating 'resident' population, comprising two distinct communities, and the marine mammal-eating 'transient' killer whale population, provided an invaluable reference for the interpretation of contaminant concentrations. Total PCB concentrations (sum of 136 congeners detected) were surprisingly high in all three communities, but transient killer whales were particularly contanimated. PCB concentrations increaed with age in males, but were greatly reduced in reproductively active females. The absence of age, sex and inter-community differences in concentrations of polychlorinated- dibenzo-p-dioxins (PCDDs) and- dibenzofurans (PCDFs) may have partly reflected low dietary levels, but more importantly, metabolic removal of dioxin-like compounds in killer whales. While information on toxic thresholds does not exist for PCBs in cetaceans, total 2,3,7,8-TCDD Toxic Equivalent (TEQ) in most killer whales sampled easily surpassed adverse effectslevels established for harbour seals, suggesting that the majority of free-ranging killer whales in this region are at risk for toxic effects. The southern resident and transient killer whales of British Columbia can now be considered among the most contaminated cetaceans in the world.7) Saulitis, Eva, Lance Barrett-Lennard, Kathy Heise, Graeme Ellis. (2000). Foraging strategies of sympatric killer whale (Orcinus orca) populations in Prince William Sound, Alaska. Marine Mammal Science 16 (1), 94–109.
Abstract
Killer whales (Orcinus orca) feed on a wide variety of fish, cephalopods, and marine mammals throughout their cosmopolitan range; however, the dietary breadth that characterizes the species is not reflected in all populations. Here, we present the findings of a 14-yr study of the diet and feeding habits of killer whales in Prince William Sound, Alaska. Two non-associating forms of killer whale, termed resident and transient (Bigg et al. 1987), were identified. All prey seen taken by transients were marine mammals, including harbor seals (Phoca vitulina), Dall's porpoises (Phocoenoides dalli), Steller sea lions (Eumetopias jubatus), and harbor porpoises (Phocoena phocoena). Resident killer whales appeared to prey principally on salmon (Oncorhynchus spp.), preferring coho salmon (O. kisutch) over other, more abundant salmon species. Pacific herring (Clupea pallasi) and Pacific halibut (Hippocampus stenolepis) were also taken. Resident killer whales frequently were seen to interact in non-predatory ways with Steller sea lions and Dall's porpoises, while transients were not. Differences in the social organization and behavior of the resident and transient killer whales in Prince William Sound are discussed in the light of the dietary differences documented here.8) Scheel, D.; Craig O. Matkin and Eva Saulitis. (2001). Distribution of killer whale (Orcinus orca) pods in Prince William Sound, Alaska 1984-1996. Marine Mammal Science 17(3):555-569.
Abstract
Thirteen years of encounter data (19841996) were used to examine killer whale distribution within Prince William Sound, Alaska. Four patterns of area use were found, which comprised differences between resident pods and transient groups and differences among resident groups. Resident pods frequented large open passages, while transient groups used the narrow passages and bays in the southwest. This dichotomy likely reflects reside nt use of salmon and transient use of pinniped prey resources, as well as th e different foraging strategies required for these prey types. Four resident pods (AB, AI, AJ, and AN) used Knight Island Passage more than other areas of the Sound; two (AE and AK) used all areas of the Sound more evenly. Use of the Sound by the AT1 transient whales declined in the latter part of the study. Nearshore foraging for pinniped prey by the AT1 transient whales was more common in areas where these whales spend a disproportionate amount of time, suggesting that these areas were critical foraging habitat for them.
No similar pattern emerged for Open-water Foraging for cetaceans by AT1 whales, nor for foraging by the resident whales.9) Hoelzel, A. Rus, Ada Natoli, Marilyn E. Dahlheim, Carlos Olavarria, Robin W. Baird and Nancy A. Black. (2002). Low worldwide genetic diversity in the killer whale (Orcinus orca): implications for demographic history. Proc. Royal Soc. B 269: 1467-1475.
Abstract
A low level of genetic variation in mammalian populations where the census population size is relatively large has been attributed to various factors, such as a naturally small effective population size, historical bottlenecks and social behaviour. The killer whale (Orcinus orca) is an abundant, highly social species with reduced genetic variation. We find no consistent geographical pattern of global diversity and no mtDNA variation within some regional populations. The regional lack of variation is likely to be due to the strict matrilineal expansion of local populations. The worldwide pattern and paucity of diversity may indicate a historical bottleneck as an additional factor.
Full Paper: (PDF)10) Dr. Peter S. Ross, Fisheries and Oceans Canada (2002)
Marine Ecosystem Health Program (MEHP)
Killer whales as sentinels of marine ecosystem contaminationAbstract
The southern resident killer whale (Orcinus orca) population depends on the availability of prey in the shared coastal waters of Washington state and the province of British Columbia during much of the year. Declining population numbers (down 20% since 1996) have raised concerns in both Canada and the United States, leading to a threatened listing in Canada in 1999 and a recent petition to list this population under the terms of U.S. Endangered Species Act (ESA). Reports have cited diminishing prey (salmon) abundance, heavy vessel traffic and high contaminant levels. Contaminants including PCBs have been associated with adverse health effects in both humans and wildlife, including endocrine disruption, immunotoxicity and reproductive impairment. Our recent report citing northeast Pacific killer whales as among the most contaminated in the world underscores the need to better understand the source of toxic chemicals and their fate in killer whales at the top of the coastal food chain. We have initiated a two-year MEHP project (Year One: 2001; Year Two, this proposal: 2002) to evaluate the levels and patterns of Persistent Organic Pollutants (POPs; approximately 250 chemicals, including the PCBs, dioxins and pesticides) in the primary dietary component of southern resident killer whales, Chinook salmon. In Year One, we initiated a graduate student research project, set up working relationships with several laboratories, conducted preliminary experiments on stable isotopes and fatty acids, collected Chinook smolts and adults from two stocks in Puget Sound, subsampled and prepared tissues for contaminant and other analyses. Contaminant analysis is currently underway. In Year Two, we plan to complete fatty acid and stable isotope analyses, interpret data from these and contaminant analysis in the context of Chinook life history and ecology, killer whale data and food chain structure. This work will help to assess the relative importance of local vs. offshore sources of contaminants. Results will be linked to contaminant data from i) concurrent studies of Strait of Georgia fish; ii) southern resident killer whales; and iii) Puget Sound harbor seals. Results will be further interpreted using multivariate statistical evaluation of contaminant patterns and a food chain bioaccumulation model. Results will also be related to our ongoing research into the effects of POPs on the health of killer whales. This project will help to bridge Canadian and U.S. approaches to assessing contaminant levels in shared waters. Results from this research will be provided to stakeholders by way of a dedicated website and a published fact sheet. In this manner, we plan to better understand the state of contamination of the marine ecosystem in Puget Sound, the Strait of Georgia and Juan de Fuca Strait, and the risk that this contamination presents to killer whales and other high trophic level consumers.11) Williams, Rob, Andrew W. Trites, and David E. Bain. (2002). Behavioural responses of killer whales (Orcinus orca) to whale-watching boats: opportunistic observations and experimental approaches. Journal of Zoology, 256: 255-270.
Abstract
Johnstone Strait provides important summer habitat for the northern resident killer whales Orcinus orca of British Columbia. The site is also an active whale-watching area. A voluntary code of conduct requests that boats do not approach whales closer than 100 m to address perceived, rather than demonstrated, effects of boat traffic on killer whales. The purpose of the study was to test the relevance of this distance guideline. Relationships between boat traffic and whale behaviour were studied in 1995 and 1996 by shore-based theodolite tracking of 25 identifiable focal animals from the population of 209 whales. Individual killer whales were repeatedly tracked in the absence of boats and during approaches by a 5.2 m motorboat that paralleled each whale at 100 m. In addition, whales were tracked opportunistically, when no effort was made to manipulate boat traffic. Dive times, swim speeds, and surface-active behaviours such as breaching and spy-hopping were recorded. On average, male killer whales swam significantly faster than females. Whales responded to experimental approaches by adopting a less predictable path than observed during the preceding, no-boat period, although males and females used subtly different avoidance tactics. Females responded by swimming faster and increasing the angle between successive dives, whereas males maintained their speed and chose a smooth, but less direct, path. Canonical correlations between whale behaviour and vessel proximity are consistent with these conclusions, which suggest that weakening whale-watching guidelines, or not enforcing them, would result in higher levels of disturbance. High variability in whale behaviour underscores the importance of large sample size and extensive experimentation when assessing the impacts of human activity on killer whales.12) Pitman, Robert L. (2003). Good whale hunting: two tantalizing Russian reports take the author on a quest to the Antarctic, in search of two previously unrecognized kinds of killer whale. Natural History, December 2003.
Abstract
After three seasons in Antarctica, I am convinced that in addition to the familiar killer whale from around the world, at least one and probably two additional species of killer whale lurk in the icy waters around the cold continent. What I have seen are three quite different-looking forms, which have different, but at times overlapping, ranges and habitats. The three forms also prefer different prey and travel together in herds of different size (the latter behavior suggests their social structure is probably different, too). And though there are no discernible physical barriers to prevent intermingling or interbreeding, I have never seen mixed herds or any individual that looks like an intermediate form, or hybrid. The failure to find any social mixing or apparent hybrids is highly significant in itself.
Like the earlier reports of the Soviets, these conclusions will be met with healthy skepticism by other marine-mammal scientists. To meet this challenge I have already begun some collaborative studies on the genetics, vocalizations, and morphology of Antarctic killer whales that will bring additional evidence to bear on these issues. The preliminary analysis of the tissue samples I have collected, for instance, already suggests that the three forms may not interbreed, but the results are still preliminary and verification will take a while. There are no simple answers.13) Marino, Lori; Chet C. Sherwood, Bradley N. Delman, Cheuk Y. Tang, Thomas P. Naidich, Patrick R. Hof. (2004). Neuroanatomy of the killer whale (Orcinus orca) from magnetic resonance images. Anat Rec 281A, 2:1256-1263 264:397-414, 2004.
Abstract
This article presents the first series of MRI-based anatomically labeled sectioned images of the brain of the killer whale (Orcinus orca). Magnetic resonance images of the brain of an adult killer whale were acquired in the coronal and axial planes. The gross morphology of the killer whale brain is comparable in some respects to that of other odontocete brains, including the unusual spatial arrangement of midbrain structures. There are also intriguing differences. Cerebral hemispheres appear extremely convoluted and, in contrast to smaller cetacean species, the killer whale brain possesses an exceptional degree of cortical elaboration in the insular cortex, temporal operculum, and the cortical limbic lobe. The functional and evolutionary implications of these features are discussed.14) Rayne, Sierra, Michael G. Ikonomou, Peter S. Ross, Graeme M. Ellis, Lance G. Barrett-Lennard. (2004). PBDEs, PBBs, and PCNs in Three Communities of Free-Ranging Killer Whales (Orcinus orca) from the Northeastern Pacific Ocean. American Chemical Society.
Abstract
Polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and polychlorinated naphthalenes (PCNs) were quantified in blubber biopsy samples collected from free-ranging male and female killer whales (Orcinus orca) belonging to three distinct communities (southern residents, northern residents, and transients) from the northeastern Pacific Ocean. High concentrations of PBDE were observed in male southern residents (942 ± 582 ng/g lw), male and female transients (1015 ± 605 and 885 ± 706 ng/g lw, respectively), and male and female northern residents (203 ± 116 and 415 ± 676 ng/g lw, respectively). Because of large variation within sample groups, PBDE levels generally did not differ statistically with the exception of male northern residents, which had lower PBDE concentrations than male southern residents, male transients, and female transients, perhaps reflecting the consumption of less contaminated prey items. Male transient killer whales, which consume high trophic level prey including other cetaceans and occasionally spend time near populated areas, had PBDE concentrations approximately equal to southern residents. No significant age-related relationships were observed for PBDE concentrations. PBDE concentrations were approximately 1-3 orders of magnitude greater than those of PBB (3.0-31 ng/g lw) and PCN (20-167 ng/g lw) measured in a subset of samples, suggesting that PBDEs may represent a contaminant class of concern in these marine mammals.16) Ford, John K.B., Graeme M. Ellis (2005). Prey selection and food sharing by fish-eating ‘resident’ killer whales (Orcinus orca) in British-Columbia. Canadian Science Advisory Secretariat Research Document - 2005/041.
Abstract
Three distinct, socially-isolated forms, or ecotypes, of killer whales (Orcinus orca), inhabit coastal waters of British-Columbia, Washington State, and southeastern Alaska. The so-called transient ecotype feeds primarily on marine mammal prey, the resident ecotype feeds primarily on fish, and the diet of the offshore ecotype is not known. A previous study of the diet of the resident and transient ecotypes using opportunistic collection of prey remains from kill sites as a primary measure of prey selection found that resident killer whales feed predominantly on salmonids, particularly on chinook salmon (Oncorhynchus tshawytscha). To address uncertainties concerning potential biases in the prey fragment sampling technique and questions regarding seasonal and geographic variability in diet, we conducted field studies of foraging behaviour during 1997-2004. Foraging by resident killer whales often involves cooperation among kin-related group members, and prey items are frequently shared by two or more whales. Adult males share prey less often than do females and subadults. Prey sharing does not appear to be related to prey size. Prey fragments left at kill sites result mostly from prey handling and sharing, and are reliable indicators of selection for different salmonid species by resident killer whales. Chinook is the predominant prey species taken by both northern and southern resident communities during May-August, but chum salmon (O. keta) is more prevalent in September-October, at least in northern residents. Coho salmon (O. kisutch) are taken in low numbers in June-October, but sockeye (O. nerka) and pink (O. gorbuscha) salmon are not significant prey species despite their high seasonal abundance. Non-salmonid fishes do not appear to represent an important component of resident whale diet during May-October. Their strong preference for chinook salmon may influence the year-round distribution patterns of resident killer whales in coastal British-Columbia and adjacent waters.17) Ford, John K.B., Graeme M. Ellis (2005). Selective foraging by fish-eating killer whales Orcinus orca in British Columbia. (2006). MARINE ECOLOGY PROGRESS SERIES Vol. 316: 185–199, 2006.
Abstract
As the apex non-human marine predator, the killer whale Orcinus orca feeds on a wide diversity of marine fauna. Different ecotypic forms of the species, which often exist in sympatry, may have distinct foraging specialisations. One form found in coastal waters of the temperate NE Pacific Ocean, known as the ‘resident’ ecotype, feeds predominantly on salmonid prey. An earlier study that used opportunistic collection of prey remains from kill sites as an indicator of predation rates suggested that resident killer whales may forage selectively for chinook salmon Oncorhynchus tshawytscha, the largest but one of the least abundant Pacific salmon species. Potential biases in the prey fragment sampling technique, however, made the validity of this finding uncertain. We under-took field studies of foraging behaviour of resident killer whales to resolve this uncertainty and to examine potential variation in prey selection by season, geographical area, group membership and prey availability. Foraging by resident killer whales was found to frequently involve sharing by 2 or more whales. Prey fragments left at kill sites resulted mostly from handling and breaking up of prey for sharing, and all species and sizes of salmonids were shared. Resident killer whale groups in all parts of the study area foraged selectively for chinook salmon, probably because of the species’ large size, high lipid content, and year-round availability in the whales’ range. Chum salmon Oncorhynchus keta, the second largest salmonid, were also taken when available, but smaller sock-eye O. nerka and pink O. gorbuscha salmon were not significant prey despite far greater seasonal abundance. Strong selectivity for chinook salmon by resident killer whales probably has a significant influence on foraging tactics and seasonal movements, and also may have important implications for the conservation and management of both predator and prey.18) Ford, J.K.B., G.M. Ellis, P.F. Olesiuk. (2005). Linking Prey and Population Dynamics: did food limitation cause recent declines of 'resident' killer whales (Orcinus orca) in British Columbia?
Abstract
Two populations of fish-eating killer whales (Orcinus orca) in British Columbia, known as residents, are listed under the Canadian Species-at-Risk Act due to their small population size and recent unexplained declines in abundance. Threats considered to potentially affect survival and recovery of these populations include environmental pollutants, physical and acoustic disturbance, and reductions in the availability or quality of salmonids, their primary prey. Recent studies have shown that chinook salmon and, to a lesser degree, chum salmon, are important prey for resident killer whales, but other smaller salmonid species are not. In this report, we assess whether food limitation was potentially a significant factor in recent declines of these whale populations. We examined the relationship between trends in killer whale population dynamics based on long-term photo-identification data, and abundance levels of chinook and chum salmon off the British Columbia coast over the past 25 years. Resident killer whale population productivity is regulated primarily by changes in survival. Periods of decline were primarily due to unusually high mortality rates that were experienced by all age- and sex-classes of whales and were synchronous in the socially-isolated two resident communities. Fluctuations in observed versus expected mortality rates showed a strong correlation with changes in chinook salmon abundance, but no relationship to chum salmon abundance. A sharp drop in coast-wide chinook abundance during the late 1990s was closely associated with a significant decline in resident whale survival. The whales’ preference for chinook salmon is likely due to this species’ relatively large size, high lipid content and, unlike other salmonids, its year-round presence in the whales’ range. Resident killer whales may be especially dependent on chinook during winter, when this species is the primary salmonid available in coastal waters, and the whales may be subject to nutritional stress leading to increased mortality if the quantity and/or quality of this prey resource declines. Chinook salmon is clearly of great importance to resident killer whales, but determining whether the species is the principal factor limiting whale productivity will require on-going monitoring of both salmon and whale population trends.19) Baird, R.W., D.J. McSweeney, C. Bane, J. Barlow, D.R. Salden, L.K. Antoine, R.G. LeDuc and D.L. Webster. (2006). Killer whales in Hawaiian waters: information on population identity and feeding habits.
Abstract
Killer whales (Orcinus orca) have only infrequently been reported from Hawaiian waters, and most of what is known about killer whales world-wide comes from studies in coastal temperate waters. Here we document 24 records of killer whales from within the Hawaiian Exclusive Economic Zone between 1994 and 2005. Killer whales were recorded 10 months of the year, most around the main Hawaiian Islands. While there were slightly more records than expected during the period when humpback whales are abundant around the islands, there is likely an increase in sighting effort during this period. Killer whales were documented feeding on both a humpback whale and cephalopods, and two species of small cetaceans were observed fleeing from killer whales. Although it is possible there are both marine mammal-eating and cephalopod-eating populations within Hawaiian waters, it seems more likely that Hawaiian killer whales may not exhibit foraging specializations as documented for coastal temperate populations, given the lower productivity and thus reduced selective pressure for specialization in tropical waters. Saddle patch pigmentation patterns were generally fainter and narrower than for those seen in killer whales from the temperate coastal North Pacific, though were most similar to the mammal-eating form of killer whale from those areas. Analysis of skin samples from two animals indicated two mitochondrial haplotypes, one identical to the "Gulf of Alaska transient 2" haplotype (a mammal-eating form), and the other a new haplotype one base different from haplotypes found for mammal-eating killer whales in coastal Alaskan waters. While more samples are needed, including samples from intervening areas, we suggest that killer whales around the Hawaiian Islands are likely isolated from populations in coastal temperate areas.
PDF copies are available at:
http://www.cascadiaresearch.org/robin/hawaii.htm20) Morin, Phillip A. Richard G. LeDuc, Kelly M. Robertson, Nicole M. Hedrick, William F. Perrin, Michael Etnier, Paul Wade, Barbara L. Taylor. (2006). Genetic analysis of killer whale (Orcinus Orca) historical bone and tooth samples to identify western U.S. ecotypes. Marine Mammal Science, Volume 22 Issue 4 Page 897 - October.
Abstract
Little is known about the historical range of killer whale ecotypes in the eastern North Pacific (ENP). It is possible that ranges have shifted in the last few decades because of changes in availability of food. In particular, the southern resident ecotype, currently found primarily in the inland waters of Washington State, is known to prey extensively on salmon, which have declined in recent decades along the outer coasts of Washington, Oregon, and California. To investigate historical distributions of this and the other ENP ecotypes, samples of teeth and bones were obtained from NMFS and museum collections. We amplified a short section of the mitochondrial DNA control region that contains four diagnostic sites that differentiate between haplotypes found in ecotypes of ENP killer whales. Results did not show any southern resident haplotypes in samples from south of the Washington State inland waterways. One whale genetically identified as a northern resident extends the known southernmost distribution of the population from Oregon to California. Items of diet identified from stomach contents of six of the whales genetically identified to ecotype conformed with what is known of the feeding habits of the various ecotypes.
Full paper available here:
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1748-7692.2006.00070.x21) Nousek, Anna E., Peter J.B. Slater, Chao Wang, Patrick J.O. Miller.2006. The influence of social affiliation on individual vocal signatures of northern resident killer whales (Orcinus orca). Royal Society Journal.
Abstract
Northern resident killer whales (Orcinus orca) live in highly stable groups and use group-specific vocal signals, but individual variation in calls has not been described previously. A towed beam-forming array was used to ascribe stereotyped pulsed calls with two independently modulated frequency contours to visually identified individual killer whales in Johnstone Strait, British Columbia. Overall, call similarity determined using neural networks differed significantly between different affiliation levels for both frequency components of all the call types analysed. This method distinguished calls from individuals within the same matriline better than different calls produced by a single individual and than chance. The calls of individuals from different matrilines were more distinctive than those within the same matriline, confirming previous studies based on group recordings. These results show that frequency contours of stereotyped calls differ among the individuals that are constantly associated with each other and use group-specific vocalizations, though across-group differences were substantially more pronounced.
22) Zerbini, Alexandre N., Janice M. Waite, John W. Durban, Rick LeDuc, Marilyn E. Dahlheim and Paul R. Wade. (2006). Estimating abundance of killer whales in the nearshore waters of the Gulf of Alaska and Aleutian Islands using line-transect sampling. Marine Biology: 9 August 2006.Abstract
Killer whale (/Orcinus orca/ Linnaeus, 1758) abundance in the North Pacific is known only for a few populations for which extensive longitudinal data are available, with little quantitative data from more remote regions. Line-transect ship surveys were conducted in July and August of 2001 - 2003 in coastal waters of the western Gulf of Alaska and the Aleutian Islands. Conventional and Multiple Covariate Distance Sampling methods were used to estimate the abundance of different killer whale ecotypes, which were distinguished based upon morphological and genetic data. Abundance was calculated separately for two data sets that differed in the method by which killer whale group size data were obtained. Initial group size (IGS) data corresponded to estimates of group size at the time of first sighting, and post-encounter group size (PEGS) corresponded to estimates made after closely approaching sighted groups.
'Resident'-type (fish-eating) killer whales were more abundant than the 'transient'-type (mammal-eating). Abundance estimates of resident killer whales (991 [95% CI = 379-2,585] [IGS] and 1,587 [95% CI = 608-4,140] [PEGS]), were at least four times greater than those of the transient killer whales (200 [95% CI = 81-488] [IGS] and 251 [95% CI = 97-644] whales [PEGS]). The IGS estimate of abundance is preferred for resident killer whales because the estimate based on PEGS data may show an upward bias. The PEGS estimate of abundance is likely more accurate for transients. Residents were most abundant near Kodiak Island in the northern Gulf of Alaska, around Umnak and Unalaska Islands in the eastern Aleutians, and in Seguam Pass in the central Aleutians. This ecotype was not observed between 156 and 164°W, south of the Alaska Peninsula.23) Burdin, Alexander M., Erich Hoyt, Olga A. Filatova, Tatyana Ivkovich, Karina Tarasyan and Hal Sato (2007). Status of Killer Whales (Orcinus orca) in Eastern Kamchatka (Russian Far East) Based on Photo-Identification and Acoustic Studies. Preliminary Results. SC/59/SM4.
Abstract
From 1999-2006, a long-term study of killer whales (Orcinus orca) off eastern Kamchatka has conducted photoidentification and acoustic studies from a field station in Avacha Gulf. From 2002-2005, wide-area large ship surveys have expanded the study to other regions in the Russian Far East (RFE) including: northeast Kamchatka, Commander Islands, Chukotka, Kuril Islands and northeast Sakhalin. In this paper we mainly discuss the killer whale status on the eastern coast of Kamchatka, and give a brief review of available information regarding the killer whale status in other areas of the RFE. During the field seasons 2005-2006, a total of 434 individuals were identified in Avacha Gulf in at least three acoustic clans with different dialects. Most are resident-type fish-eating whales. Some transient-type marine mammal eating whales have also been recorded in Avacha Gulf and in other areas of the RFE. Transients as well as some residents show bites from the cookie cutter shark (Isistius brasiliensis) which may indicate long distance travel along the Asian coast or out to sea. To date, live captures have removed at least two subadult females from the Avacha Gulf residents. A live-capture quota of 6-10 killer whales in the RFE has been granted every year since 2002 (8 for 2007) although data remain inadequate to support this. The conflict between whales and fishermen in the Sea of Okhotsk due to killer whale depredation merits further study.
Free PDF copy:
http://iwcoffice.org/_documents/sci_com/SC59docs/SC-59-SM4.pdf24) Hickie, Brendan E., Peter S. Ross, Robie W. Macdonald, and John K. B. Ford (2007). Killer Whales (Orcinus orca) Face Protracted Health Risks Associated with Lifetime Exposure to PCBs. Environ. Sci. Technol., 41 (18), 6613 -6619.
Abstract
Polychlorinated biphenyl (PCB) concentrations declined rapidly in environmental compartments and most biota following implementation of regulations in the 1970s. However, the metabolic recalcitrance of PCBs may delay responses to such declines in large, long-lived species, such as the endangered and highly PCB-contaminated resident killer whales (Orcinus orca) of the Northeastern Pacific Ocean. To investigate the influence of life history on PCB-related health risks, we developed models to estimate PCB concentrations in killer whales during the period from 1930 forward to 2030, both within a lifetime (~50 years) and across generations, and then evaluated these in the context of health effects thresholds established for marine mammals. Modeled PCB concentrations in killer whales responded slowly to changes in loadings to the environment as evidenced by slower accumulation and lower magnitude increases in PCB concentrations relative to prey, and a delayed decline that was particularly evident in adult males. Since PCBs attained peak levels well above the effects threshold (17 mg/kg lipid) in ~1969, estimated concentrations in both the northern and the more contaminated southern resident populations have declined gradually. Projections suggest that the northern resident population could largely fall below the threshold concentration by 2030 while the endangered southern residents may not do so until at least 2063. Long-lived aquatic mammals are therefore not protected from PCBs by current dietary residue guidelines.25) Krahn, Margaret M., M. Bradley Hanson, Robin W. Baird, Richard H. Boyer, Douglas G. Burrows, Candice K. Emmons, John K.B. Ford, Linda L. Jones, Dawn P. Noren, Peter S. Ross, Gregory S. Schorr, Tracy K. Collier (2007). Persistent organic pollutants and stable isotopes in biopsy samples (2004/2006) from Southern Resident killer whales. Marine Pollution Bulletin.
Abstract
"Southern Resident" killer whales include three "pods" (J, K and L) that reside primarily in Puget Sound/Georgia Basin during the spring, summer and fall. This population was listed as "endangered" in the US and Canada following a 20% decline between 1996 and 2001. The current study, using blubber/epidermis biopsy samples, contributes contemporary information about potential factors (i.e., levels of pollutants or changes in diet) that could adversely affect Southern Residents. Carbon and nitrogen stable isotopes indicated J- and L-pod consumed prey from similar trophic levels in 2004/2006 and also showed no evidence for a large shift in the trophic level of prey consumed by L-pod between 1996 and 2004/2006. PPCBs decreased for Southern Residents biopsied in 2004/2006 compared to 1993-1995. Surprisingly, however, a three-year-old male whale (J39) had the highest concentrations of PPBDEs, PHCHs and HCB. POP ratio differences between J- and L-pod suggested that they occupy different ranges in winter.26) Pitman, Robert L., Wayne L. Perryman, Don Leroi, and Erik Eilers (2007) A dwarf form of killer whale in Antarctica. Journal of Mammalogy, 88(1):43–48.
Abstract
In the early 1980s, 2 groups of Soviet scientists independently described 1, possibly 2 new dwarf species of killer whales (Orcinus) from Antarctica. We used aerial photogrammetry to determine total length (TL) of 221 individual Type C killer whales—a fish-eating ecotype that inhabits dense pack ice—in the southern Ross Sea in January 2005. We confirmed it as one of the smallest killer whales known: TL of adult females (with calves) averaged 5.2 m ± 0.23 SD (n = 33); adult males averaged 5.6 ± 0.32 m (n = 65), with the largest measuring 6.1 m. Female Type A killer whales—offshore mammal-eaters—from Soviet whaling data in the Southern Ocean were approximately 1–2 m longer, and males were 2–3 m (up to 50%) longer (maximum length 9.2 m). Killer whale communities from the North Atlantic and in waters around Japan also appear to support both a smaller, inshore, fish-eating form and a larger, offshore, mammal-eating form. We suggest that, at least in Antarctica, this degree of size dimorphism could result in reproductive isolation between sympatric ecotypes, which is consistent with hypotheses of multiple species of killer whales in the Southern Ocean.
Full paper here:
http://www.cryptomundo.com/wp-content/uploads/dwarfkillerwhalejmam2007.pdf27) Steiger, G.H., J. Calambokidis, J.M. Straley, L.M. Herman, S. Cerchio, D.R. Salden, J. Urbán-R, J.K. Jacobsen, O. von Ziegesar, K.C. Balcomb, C.M. Gabriele, M.E. Dahlheim, S. Uchida, J.K.B. Ford, P. Ladron de Guevara-P, M. Yamaguchi and J. Barlow. (2008). Geographic variation in killer whale attacks on humpback whales in the North Pacific: implications for predation pressure. Endangered Species Research 4:247-256.
Abstract
We examined the incidence of rake mark scars from killer whales Orcinus orca on the flukes of humpback whales Megaptera novaeangliae throughout the North Pacific to assess geographic variation in predation pressure. We used 3650 identification photographs from 16 wintering or feeding areas collected during 1990 to 1993 to determine conservative estimates in the percentage of whales with rake mark scarring. Dramatic differences were seen in the incidence of rake marks among regions, with highest rates on wintering grounds off Mexico (26 vs. 14% at others) and feeding areas off California (20 vs. 6% at others), 2 areas between which humpback whales migrate. Although attacks are rarely witnessed, the prevalence of scars demonstrates that a substantial portion of animals are attacked, particularly those that migrate between California and Mexico. Our data also suggest that most attacks occur at or near the wintering grounds in the eastern North Pacific. The prevalence of attacks indicates that killer whale predation has the potential to be a major cause of mortality and a driving force in migratory behavior; however, the location of the attacks is inconsistent with the hypothesis that animals migrate to tropical waters to avoid predation. Our conclusion is that, at least in recent decades, attacks are made primarily on calves at the wintering grounds; this contradicts the hypothesis that killer whales historically preyed heavily on large whales in high-latitude feeding areas in the North Pacific.
28) Matkin, C.O., E.L. Saulitas, G.M. Ellis, P. Olesiuk, S.D. Rice. (2008). Ongoing population-level impacts on killer whales Orcinus orca following the 'Exxon Valdez' oil spill in Prince William Sound, Alaska. Mar Ecol Prog Ser, Vol. 356: 269-281, 2008.
Abstract
Killer whales were photographed in oil after the 1989 ‘Exxon Valdez’ oil spill, but preliminary damage assessments did not definitively link mortalities to the spill and could not evaluate recovery. In this study, photo-identification methods were used to monitor 2 killer whale populations 5 yr prior to and for 16 yr after the spill. One resident pod, the AB Pod, and one transient population, the AT1 Group, suffered losses of 33 and 41%, respectively, in the year following the spill. Sixteen years after 1989, AB Pod had not recovered to pre-spill numbers. Moreover, its rate of increase was significantly less than that of other resident pods that did not decline at the time of the spill. The AT1 Group, which lost 9 members following the spill, continued to decline and is now listed as depleted under the Marine Mammal Protection Act. Although there may be other contributing factors, the loss of AT1 individuals, including reproductive-age females, accelerated the population’s trajectory toward extinction. The synchronous losses of unprecedented numbers of killer whales from 2 ecologically and genetically separate groups and the absence of other obvious perturbations strengthens the link between the mortalities and lack of recovery, and the ‘Exxon Valdez’ oil spill.
Government agency recovery plans:
National Oceanic and Atmospheric Administration (USA):
• Puget Sound Killer Whale ESA Recovery Plan (LINK)
Department of Fisheries and Oceans (Canada):
• Recovery Strategy for Northern and Southern Resident Killer Whales (LINK)
Recent publications:
• National Marine Fisheries Service. (2008). Plan for Southern Resident Killer Whales (Orcinus orca). National Marine Fisheries Service, Northwest Region, Seattle, Washington. (PDF)