Center for Whale Research

CWR Aerial Observation Study drone footage of Southern Resident orcas J38, J22, J58, J19, J51, and J41 traveling along the west side of San Juan Island in October of 2022.

RESEARCH

For over 40 years, the Center for Whale Research (CWR) has been the leading organization studying the Southern Resident killer whales (SRKW). Our scientific research has created the longest-running data set about the Southern Residents’ behavior, health, and social dynamics.

Our studies and regular health assessments of the gravely endangered Southern Resident orca population uniquely qualify us to provide evidence-based direction to elected officials about conservation objectives that will meet the whales’ critical Salish Sea habitat needs.

Our scientists’ exhaustive examination of the Salish Sea’s SRKWs and Bigg’s orcas has resulted in regular peer-reviewed papers published in leading scientific journals, and government reports that have guided conservation policies.

In many aquatic taxa, formation traveling can reduce the energetic expenditure of locomotion by exploiting the vorticity trails shed by neighbors or through drafting. Cetaceans, especially odontocetes, often swim in groups; nevertheless, the possibility that whales gain energetic benefits from swimming in formation remains poorly studied, apart from mother-calf pairs. Full Text

Understanding how and why menopause has evolved is a long-standing challenge across disciplines. Females can typically maximize their reproductive success by reproducing for the whole of their adult life. In humans, however, women cease reproduction several decades before the end of their natural lifespan1,2. Although progress has been made in understanding the adaptive value of menopause in humans3,4, the generality of these findings remains unclear. Full Text

Grimes et al. show that in resident killer whales, socially inflicted injuries are lower for males in the presence of their postreproductive mothers. The same effect is not observed in females, providing evidence that social support is directed toward male offspring, and may be a key pathway by which postreproductive females help their relatives. Full Text

Peer-reviewed published SCIENTIFIC RESEARCH

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June 2024 I SPRINGER LINK
The effect of formation swimming on tailbeat and breathing frequencies in killer whales

March 2024 I nature
The evolution of menopause in toothed whales

August 2023 I Current Biology
Postreproductive female killer whales reduce socially inflicted injuries in their male offspring

KILLER WHALES/ORCAS

Spina, F., Weiss, M. N., Croft, D. P., Luschi, P., Massolo, A., and Domenici, P. (2024). The effect of formation swimming on tailbeat and breathing frequencies in killer whales. SPRINGER LINK, Volume 78, article number 75. Full Text.

Ellis, S., Franks, D.W., Nielsen, M.L.K., Weiss, M. N., and Croft, D. P. (2024). The evolution of menopause in toothed whales. Nature, March 2024. Full Text.

Grimes, C., Brent, L. J. N., Ellis, S., Weiss, M. N., Franks, D. W., Ellifrit, D. K., and Croft, D. P. (2023). Postreproductive female killer whales reduce socially inflicted injuries in their male offspring. Current Biology 33, 1–7. Full Text.

Nielsen, M. L. K., Ellis, S., Weiss, M. N., Towers, J. R., Doniol-Valcroze, T., Franks, D. W., Cant, M. A., Ellis, G. M., Ford, J. K. B., Malleson, M., Sutton, G., Shaw, T. J. H., Balcomb, K. C., Ellifrit, D. K., and Croft, D. P. (2023). Temporal dynamics of mother–offspring relationships in Bigg’s killer whales: opportunities for kin-directed help by post-reproductive females. Proceedings of the Royal Society B, Volume 290 Issue 2000. Full Text.

Weiss, M. N., Ellis, S., Franks, D. W., Nielsen, M. L. K., Cant, M. A., Johnstone, R. A., Ellifrit, D. K., Balcomb, K. C., and Croft, D. P. (2023). Costly lifetime maternal investment in killer whales. Current Biology 33, 1–5. Full Text.

Grimes, C., Brent, L. J. N., Weiss, M. N., Franks, D. W., Balcomb, K. C., Ellifrit, D. K., Ellis, S., and Croft, D. P. (2022). The effect of age, sex, and resource abundance on patterns of rake markings in resident killer whales (Orcinus orca). Marine Mammal Science, 2022;1–18. Full Text.

Nielsen, M. L. K., Ellis, S., Towers, J. R., Doniol-Valcroze, T., Franks, D. W., Cant, M. A., Weiss, M. N., Johnstone, R. A., Balcomb, K. C., Ellifrit, D. K., and Croft, D. P. (2021). A long postreproductive life span is a shared trait among genetically distinct killer whale populations. Ecology and Evolution 11(13): 9123-9136. Full Text.

Weiss, M. N., Franks, D. W., Giles, D. A., Youngstrom, S., Wasser, S. K., Balcomb, K. C., Ellifrit, D. K., Domenici, P., Cant, M. A., Ellis, S., Nielsen, M. L. K., Grimes, C., and Croft, D. P. (2021). Age and sex influence social interactions, but not associations, within a killer whale pod. Proceedings of the Royal Society B, Volume 288 Issue 1953. Full Text.

Ellis, S., Franks, D. W., Weiss, M. N., Cant, M. A., Domenici, P., Balcomb, K. C., Ellifrit, D. K. and Croft, D. P. (2021) Mixture models as a method for comparative sociality: social networks and demographic change in resident killer whales. Behavioral Ecology and Sociobiology 75, Article number: 75. Full Text.

Weiss, M. N., Franks, D. W., Balcomb, K. C., Ellifrit, D. K., Silk, M. J., Cant, M. A., and Croft, D. P. (2020). Modelling cetacean morbillivirus outbreaks in an endangered killer whale population. Biological Conservation 242: 108398. Full Text.

Nattrass, S., Croft, D. P., Ellis, S., Cant, M. A., Weiss, M. N., Wright, B, M., Stredulinsky, E., Doniol-Valcrozef, T., Ford, J. K. B., Balcomb, K. C., & Franks, D. W. (2019). Postreproductive killer whale grandmothers improve the survival of their grandoffspring. PNAS. Full Text.

Ellis, S., Franks, D. W., Nattrass, S., Currie, T. E., Cant, M. A., Giles, D., Balcomb, K. C., & Croft, D. P. (2018). Analyses of ovarian activity reveal repeated evolution of post-reproductive lifespans in toothed whales. Scientific Reports, 8(1). Full Text.

Ford, M. J., Parsons, K. M., Ward, E. J., Hempelmann, J. A., Emmons, C. K., Hanson, M. B., Balcomb, K. C., & Park, L. K. (2018). Inbreeding in an endangered killer whale population. Animal Conservation 21(5): 423-432.

Ellis, S., Franks, D. W., Nattrass, S., Cant, M. A., Bradley, D. L., Giles, D., Balcomb, K. C., & Croft D. P. (2018). Postreproductive lifespans are rare in mammals. Ecology and Evolution 8(5): 2482-2494. Full Text.

Fearnbach, H., Durban, J. W., Ellifrit, D. K., & Balcomb, K. C. (2018). "Using aerial photogrammetry to detect changes in body condition of endangered southern resident killer whales." Endangered Species Research 35: 175-180. Full Text.

Ellis, S., Franks, D.W., Nattrass, S., Cant, M.A., Weiss, M.N., Giles, D., Balcomb, K.C., & Croft, D.P. (2017). Mortality risk and social network position in resident killer whales: sex differences and the importance of resource abundance. Proceedings of the Royal Society B: Biological Sciences, 284(1865), 20171313-20171313. Full Text.

Wasser, S. K., Lundin, J. I., Ayres, K., Seely, E., Giles, D., Balcomb, K., Hempelmann, J., Parsons, K., & Booth, R. (2017). Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca). PloS One, 12(6), p.e0179824. Full Text.

Croft, D. P., Johnstone, R. A., Ellis, S., Nattrass, S., Franks, D. W., Brent, L. J. N., Mazzi, S., Balcomb, K. C., Ford, J. K. B., & Cant, M. A. (2017). Reproductive conflict and the evolution of menopause in killer whales. Current Biology, 27(2), 298–304. Full Text.

Lacy, R. C., Balcomb, K. C., Brent, L. J. N., Croft, D. P., Clark, C. W., & Paquet, P. C. (2016). Report on Population Viability Analysis model investigations of threats to the Southern Resident Killer Whale population from Trans-Mountain Expansion Project. Full Text.

Ward, E. J., Dahlheim, M. E., Waite, J. M., Emmons, C. K., Marshall, K. N., Chasco, B. E., & Balcomb, K. C. (2016). Long-distance migration of prey synchronizes demographic rates of top predators across broad spatial scales. Ecosphere, 7(2), e01276. Full Text.

Brent, L. J. N., Franks, D. W., Foster, E. A., Balcomb, K. C., Cant, M. A., & Croft, D. P. (2015). Ecological knowledge, leadership, and the evolution of menopause in killer whales. Current Biology, 25(6), 746–750. Full Text.

Cogan, J. (2015). 2015 Whale Sightings in the Salish Sea Central Salish Sea and Puget Sound. Center for Whale Research. Full Document.

Croft, D. P., Brent, L. J. N., Franks, D. W., & Cant, M. A. (2015). The evolution of prolonged life after reproduction. Trends in Ecology and Evolution, 30(7), 407–416. Full Text.

Foster, E. A., Franks, D. W., Mazzi, S., Darden, S. K., Balcomb, K. C., Ford, J. K. B., & Croft, D. P. (2012). Adaptive prolonged postreproductive life span in killer whales. Science, 337(6100), 1313–1313. Full Text.

Foster, E. A., Franks, D. W., Morrell, L. J., Balcomb, K. C., Parsons, K. M., van Ginneken, A., & Croft, D. P. (2012). Social network correlates of food availability in an endangered population of killer whales, Orcinus orca. Animal Behaviour, 83, 731–736. Full Text.

Fearnbach, H., Durban, J. W., Ellifrit, D. K., & Balcomb, K. C. (2011). Size and long-term growth trends of endangered fish-eating killer whales. Endangered Species Research, 13, 173–180. Full Text.

Ford, M. J., Hanson, M. B., Hempelmann, J. A., Ayres, K. L., Emmons, C. K., Schorr, G. S., Baird, R. W., Balcomb, K. C., Wasser, S. K., Parsons, K. M., Balcomb-Bartok, K. (2011). Inferred paternity and male reproductive success in a killer whale (Orcinus orca) population. Journal of Heredity, 102(5), 537–553. Full Text.

Ford, J. K. B., Ellis, G. M., Olesiuk, P. F., & Balcomb, K. C. (2010). Linking killer whale survival and prey abundance: food limitation in the oceans’ apex predator? Biology Letters, 6(1), 139–142. Full Text.

Parsons, K. M., Balcomb, K. C., Ford, J. K. B., & Durban, J. W. (2009). The social dynamics of southern resident killer whales and conservation implications for this endangered population. Animal Behaviour, 77(4), 963–971. Full Text.

Ward, E. J., Holmes, E. E., & Balcomb, K. C. (2009). Quantifying the effects of prey abundance on killer whale reproduction. Journal of Applied Ecology, 46(632–640). Full Text.

Ward, E. J., Parsons, K., Holmes, E. E., Balcomb Iii, K. C., & Ford, J. K. (2009). The role of menopause and reproductive senescence in a long-lived social mammal. Frontiers in Zoology, 6(4). Full Text.

Dahlheim, M. E., Schulman-Janiger, A., Black, N., Ternullo, R., Ellifrit, D., & Balcomb, K. C. (2008). Eastern temperate North Pacific offshore killer whales (Orcinus orca): Occurrence, movements, and insights into feeding ecology. Marine Mammal Science, 24(3), 719–729. Full Text.

Durban, J. W., & Parsons, K. M. (2006). Laser-metrics of free-ranging killer whales. Marine Mammal Science, 22(3), 732–743. Full Text.

Ford, J. K. B., & Ellis, G. M. (2005). Prey selection and food sharing by fish-eating “resident” killer whales (Orcinus orca) in British Columbia. Report to Fisheries and Oceans Canada. Full Text.

Ford, J. K. B., Ellis, G. M., Matkin, D. R., Balcomb, K. C., Briggs, D., & Morton, A. B. (2005). Killer whale attacks on minke whales: Prey capture and antipredator tactics. Marine Mammal Science, 21(4), 603–618. Full Text.

Ford, J. K. B., Ellis, G. M., & Olesiuk, P. F. (2005). Linking prey and population dynamics: did food limitation cause recent declines of “resident” killer whales (Orcinus orca) in British Columbia? Report to Fisheries and Oceans Canada. Full Text.

Gaydos, J. K., Balcomb, K. C., Osborne, R. W., & Dierauf, L. (2004). Evaluating potential infectious disease threats for southern resident killer whales, Orcinus orca: A model for endangered species. Biological Conservation, 117, 253–262. Full Text.

Krahn, M. M., Wade, P. R., Kalinowski, S. T., Dahlheim, M. E., Taylor, B. L., Hanson, M. B., Ylitalo, G. M., Angliss, R. P., Stein, J. E., & Waples, R. S. (2002). Status Review of Southern Resident Killer Whales (Orcinus orca) under the Endangered Species Act. NOAA Technical Memorandum NMFS Series. Full Text.

Ford, J. K. B., Ellis, G. M., & Balcomb, K. C. (2000). Killer Whales: The natural history and genealogy of Orcinus orca in British Columbia and Washington State, Second Edition. Vancouver, BC: UBC Press.

Ford, J. K. B., Ellis, G. M., Barrett-Lennard, L. G., Morton, A. B., Palm, R. S., & Balcomb, K. C. (1998). Dietary specialization in two sympatric populations of killer whales (Orcinus orca) in coastal British Columbia and adjacent waters. Canadian Journal of Zoology, 76, 1456–1471. Full Text.

Dahlheim, M. E., Ellifrit, D. K., & J. D. Swenson. (1997). Killer whales of southeast Alaska: A catalogue of photo-identified individuals. Full Text.

Brault, S., & Caswell, H. (1993). Pod-specific demography of killer whales (Orcinus orca). Ecology, 74(745), 1444–1454. Full Text.

Bigg, M. A. (1990). Social organization and genealogy of resident killer whales (Orcinus orca) in the coastal waters of British Columbia and Washington State. In P. Hammond, S. Mizroch, & G. Donovan (Eds.), Individual Recognition of Cetaceans: Use of Photo-Identification and Other Techniques to Estimate Population Parameters (pp. 383–405). Cambridge. Full Text.

Olesiuk, P. F., Bigg, M. A., & Ellis, G. M. (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, & G. P. Donovan (Eds.), Individual Recognition of Cetaceans: Use of Photo-Identification and Other Techniques to Estimate Population Parameters (pp. 209–243). Cambridge. Full Text.

Bigg, M. A. (1987). Killer Whales: A Study of Their Identification, Genealogy and Natural History in British Columbia and Washington State. Nanaimo: Phantom Press.

Balcomb, K. C., & Bigg, M. A. (1986). Population biology of three resident killer whale pods in Puget Sound and off southern Vancouver Island. In B. C. Kirkevold & J. S. Lockard (Eds.), Behavioral Biology of Killer Whales (pp. 85–95). Alan R. Liss, Inc.

Heimlich-Boran, J. R. (1986). Behavioral ecology of killer whales (Orcinus orca) in the Pacific Northwest. Canadian Journal of Zoology, 66, 565–578. Full Text.

Center for Whale Research peer-reviewed published SCIENTIFIC RESEARCH

DOLPHINS

Fearnbach, H., Durban, J., Parsons, K., & Claridge, A. D. (2012). Photographic mark–recapture analysis of local dynamics within an open population of dolphins. Ecological Applications, 22(5), 1689–1700. Full Text.

Fearnbach, H., Durban, J., Parsons, K., & Claridge, D. (2012). Seasonality of calving and predation risk in bottlenose dolphins on Little Bahama Bank. Marine Mammal Science, 28(2), 402–411.

Parsons, K. M., Durban, J. W., Claridge, D. E., Herzing, D. L., Balcomb, K. C., & Noble, L. R. (2006). Population genetic structure of coastal bottlenose dolphins (Tursiops truncatus) in the northern Bahamas. Marine Mammal Science, 22(2), 276–298. Full Text.

Parsons, K. M., Durban, J. W., Claridge, D. E., Balcomb, K. C., Noble, L. R., & Thompson, P. M. (2003). Kinship as a basis for alliance formation between male bottlenose dolphins, Tursiops truncatus, in the Bahamas. Animal Behavior, 66, 185–194.

Parsons, K. M. (2001). Reliable microsatellite genotyping of dolphin DNA from faeces. Molecular Ecology Notes, 1, 341–344.

Durban, J. W., Parsons, K. M., Claridge, D. E., & Balcomb, K. C. (2000). Quantifying Dolphin Occupancy Patterns. Marine Mammal Science, 16(4), 825–828.

Parsons, K. M., Dallas, J. F., Claridge, D. E., Durban, J. W., Balcomb, K. C., Thompson, P. M., & Noble, L. R. (1999). Amplifying dolphin mitochondrial DNA from faecal plumes. Molecular Ecology, 8, 1753–1768.

Claridge, D. E. (1994). Photo-identification study to assess the population size of Atlantic bottlenose dolphins in central Abaco. Bahamas. Journal of Science, 1, 12–16.

HUMPBACK WHALES

Calambokidis, J., Steiger, G., Straley, J., Herman, L., Cerchio, S., Salden, D., Urban R., J., Jacobsen, J., von Ziegesar, O., Balcomb, K. C., Gabriele, C., Dahlheim, M., Uchida, S., Ellis, G., Miyamura, Y., de Guevara P., P. L., Yamaguchi, M., Sato, F., Mizroch, S., Schlender, L., Barlow, J., & Quinn II, T. (2001). Movements and population structure of humpback whales in the North Pacific. Marine Mammal Science, 17(4), 769–794.

Calambokidis, J., Steigerl, G. H., Rasmussenl, K., Urban, J. R., Ladron de Guevara, P. P., Salinas, M., Jacobsen, J. K., Scott Baker, C., & Herman, L. M. (2000). Migratory destinations of humpback whales that feed off California, Oregon and Washington. Marine Ecology Progress Series, 192, 295–304.

Urban, J., Alvarez, C., Salinas, M., Jacobsen, J., Balcomb, K. C., Jaramillo, A., de Guevara, P. L., & Aguayo, A. (1999). Population size of humpback whale, Megaptera novaeangliae, in waters off the Pacific coast of Mexico. Fishery Bulletin, 97, 1017–1024.

Calambokidis, J., Steiger, G. H., Evenson, J. R., Flynn, K. R., Balcomb, K. C., Claridge, D. E., Bloedel, P., Straley, J.M., Baker, C.S., von Ziegesar, O., Dahlheim, M. E., Waite, J. M., Darling, J. D., Ellis, G., & Green, G. (1996). Interchange and isolation of humpback whales off California and other North Pacific feeding grounds. Marine Mammal Science, 12(2), 215–226.

Darling, J. D., Calambokidis, J., Balcomb, K. C., Bloedel, P., Flynn, K., Mochizuki, A., Mori, K., Sato, F., Suganuma, H., & Yamaguchi, M. (1996). Movement of a humpback whale (Megaptera novaeangliae) from Japan to British Columbia and return. Marine Mammal Science, 12(2), 281–287.

Steiger, G., Calambokidis, J., Sears, R., Balcomb, K. C., & Cubbage, J. (1991). Movement of humpback whales between California and Costa Rica. Marine Mammal Science,7(3), 306–310.

Calambokidis, J., Cubbage, J. C., Steiger, G. H., Balcomb, K. C., & Bloedel, P. (1990). Population estimates of humpback whales in the Gulf of the Farralones, California. In P. S. Hammond, S. A. Mizroch, & G. P. Donovan (Eds.), Individual Recognition of Cetaceans: Use of Photo-Identification and Other Techniques to Estimate Population Parameters (pp. 325–328). Cambridge.

BLUE WHALES

Calambokidis, J., Steiger, G. H., Cubbage, J. C., Balcomb, K. C., Ewald, C., Kruse, S., Wells, R., & Sears, R. (1990). Sightings and movements of blue whales off central California 1986-1988 from photo-identification of individuals. In P. S. Hammond, S. A. Mizroch, & G. P. Donovan (Eds.), Individual Recognition of Cetaceans: Use of Photo-Identification and Other Techniques to Estimate Population Parameters (pp. 343–349). Cambridge

BEAKED WHALES

Cox, T. M., Ragen, T. J., Read, A. J., Vos, E., Baird, R. W., Balcomb, K. C., Barlow, J., Caldwell, J., Cranford, T., Crum, L., D’amico, A., D’Spain, G., Fernandez, A., Finneran, J., Gentry, R., Gerth, W., Gullands, F., Hilderbrand, J., Houserp, D., Hullar, T., Jepson, P. D., Ketten, D., Macleod, C. D., Miller, P., Moore, S., Mountain, D. C., Palka, D., Ponganis, P., Rommel, S., Rowles, T., Taylor, B., Tyack, P., Wartzok, D., Gisiner, R., Meads, J., & Benner, L. (2006). Understanding the impacts of anthropogenic sound on beaked whales. Journal of Cetacean Resource Management, 7(3), 177–187.

GENERAL CETACEANS

Durban, J. W., Elston, D. A., Ellifrit, D. K., Dickson, E., Hammond, P. S., & Thompson, P. M. (2005). Multi-site mark-recapture for cetaceans: population estimates with Bayesian model averaging. Marine Mammal Science, 2(1), 80–92.

Durban, J. W., & Elston, D. A. (2005). Mark–recapture with occasion and individual effects: abundance estimation through bayesian model selection in a fixed dimensional parameter space. Journal of Agricultural, Biological and Environmental Statistics,10(3), 291–305. Full Text.

Parsons, K. M., & Durban, J. W. (2003). Comparing two alternative methods for sampling small cetaceans for molecular analysis. Marine Mammal Science, 19(1), 224–231.