August 21, 2011
Principal Investigator: Karen Martien, Marine Mammal Genetics Group
False killer whales (Pseudorca
crassidens) are large Delphinids typically found in deep water far
offshore. However, in the Hawaiian
Archipelago, there are two resident island-associated populations of false
killer whales, one in the waters around the main Hawaiian Islands (MHI) and one
in the waters around the Northwestern Hawaiian Islands (NWHI). The MHI population was recently listed as
Endangered under the U. S. Enangered Species Act.
We are using a variety genetic markers and methods to study
Hawaiian false killer whales. We’ve
recently completed a project using mitochondrial control region sequences and
microsatellite genotypes to examine patterns of divergence among the two island-associated
populations and offshore animals from the central and eastern North
Pacific. Our results suggest a complex
evolutionary history for the island-associated populations, with both of them
likely sharing a common colonization history, but with limited contemporary
We are also using microsatellite genotypes to examine social
structure and mating patterns with the MHI population. Photo-identification studies conducted by
Cascadia Research Collective revealed the existence of three distinct social
groups within that population. We are
using parentage analysis to determine whether or not animals stay in their
natal social group and whether mating primarily occurs between individuals from
the same social group or different social groups.
Finally, we have begun a project to use full mitochondrial
genome sequences and large numbers of SNP markers to estimate divergence times
between false killer whales from the Pacific and Atlantic Oceans, as well as
between the Hawaiian island-associated populations and the rest of the
Pacific. The result of the study could
lead to the identification of separate subspecies within the species.
Cascadia Research Collective's false killer whale page.
Status review of Hawaiian insular false killer whales (Pseudorca crassidens) under the Endangered Species Act (report of the Biological Review Team).
Baird, R.W. 2009. A review of false killer whales in Hawaiian waters: biology, status, and risk factors. Report prepared for the U.S. Marine Mammal Commision under Order No. E40475499. 49pp.
Baird, R.W., A.M. Gorgone, D.J. McSweeney, D.L. Webster, D.R. Salden, M.H. Deakos, A.D. Ligon, G.S. Schorr, J. Barlow and S.D. Mahaffy. 2008. False killer whales (Pseudorca crassidens) around the main Hawaiian Islands: long-term site fidelity, inter-island movements, and association patterns. Marine Mammal Science 24:591-612.
Baird, R.W., M.B. Hanson, G.S. Schorr, D.L. Webster, A.M. Gorgone, S.D. Mahaffy, D.M. Holzer, E.M. Oleson, R.D. Andrews. 2012. Range and primary habits of Hawaiian insular false killer whales: informing determination of critical habitat. Endangered Species Research 18:47-61.
Baird, R.W., E.M. Oleson, J. Barlow, A.D. Ligon, A.M. Gorgone, S.D. Mahaffy. 2013 Evidence of an island-associated population of false killer whales (Pseudorca crassidens) in the Northwestern Hawaiian Islands. Pacific Science 67.
Chivers, S.J., R.W. Baird, D.J. McSweeney, D.L. Webster, N.M. Hedrick and J.C. Salinas. 2007. Genetic variation and evidence for population structure in eastern North Pacific false killer whales (Pseudorca crassidens). Canadian Journal of Zoology 85:783-794.
Chivers, S.J., R.W. Baird, K.K. Martien, B.L. Taylor, E. Archer, A.M. Gorgone, B.L. Hancock, N.M. Hedrick, D. Matilla, D.J. McSweeney, E.M. Oleson, C.L. Palmer, V. Pease, K.M. Robertson, J. Robbins, J.C. Salinas, G.S. Schorr, M. Schultz, J.L. Thieleking, and D.L. Webster. Evidence of genetic differeitation for Hawaiæi Insular false killer whales (Pseudorca crassidens). NOAA Technical Memorandum 458. 49pp.