False killer whale population structure study published

For more information contact Susan Chivers at susan.chivers (at) noaa.gov or Robin W. Baird at rwbaird (at) cascadiaresearch.org

Adult false killer whale leaping while chasing prey (c) Robin W. Baird 2006. Not to be used without permission.

A paper published on-line in the Canadian Journal of Zoology on August 4, 2007, reveals that false killer whales found around the main Hawaiian Islands are genetically differentiated from false killer whales elsewhere in the tropical Pacific. This study used small skin samples collected both from free-ranging false killer whales and from animals hooked in the Hawai‘i long-line fishery to examine the genetic characteristics of false killer whales throughout the Pacific. The results were surprising, given that false killer whales are typically considered an open-ocean species and were thought to move long distances. False killer whales are a poorly-known species of toothed-whale, found throughout the tropics and sub-tropics, but are typically seen far from shore. The deep water close to shore makes the Hawaiian Islands one of the better locations to study this species, although they are only infrequently seen around the main Hawaiian Islands. Population estimates in Hawai‘i have indicated a small population size, with just a few hundred individuals. Combined with their small population size, this genetic differentiation suggests that the Hawaiian false killer whale population may be more at risk from human impacts than other more broadly-ranging species. False killer whales around the main Hawaiian Islands feed primarily on mahi mahi and other large pelagic fish, and in offshore waters they interact with the Hawai‘i long-line fishery, stealing catch and occasionally getting seriously injured or killed in the fishery.

This study was a collaborative effort between the Dr. Susan Chivers, Nicole Hedrick and Juan Carlos Salinas of the Southwest Fisheries Science Center of NOAA Fisheries located in La Jolla, California and researchers from two non-profit groups; Dr. Robin Baird of Cascadia Research Collective, based in Olympia, Washington, and Daniel McSweeney and Daniel Webster of the Wild Whale Research Foundation based in Holualoa, Hawai‘i.

More information on false killer whales and a pdf copy of the paper are available at www.cascadiaresearch.org/robin/hawaii.htm

Three adult false killer whales (c) Robin W. Baird 2006. Not to be used without permission.

False killer whales with ahi tuna (c) Daniel J. McSweeney. Not to be used without permission.

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Go to the Population Identity Program of the Southwest Fisheries Science Center