|
False killer whales with yellowfin tuna. Photo by Dan McSweeeny/Wild Whale Research Foundation |
False killer whales are a tropical and sub-tropical large odontocete (toothed whale) typically found only in the open ocean. They are uncommon everywhere, but in Hawaiian waters they utilize near-shore waters and studies of this population have been ongoing since 2000. From this work, evidence has emerged that the insular population is genetically differentiated from false killer whales in offshore Hawaiian waters (Chivers et al. 2007). Photographs obtained by researcher Dan McSweeney (of the Wild Whale Research Foundation) from the mid-1980s and 1990s have been used to demonstrate that this population has long shown fidelity to the area (Baird et al. 2008). The most recent population estimate for the insular population is just 123 individuals (Baird et al. 2005). Like the killer whale (not particularly closely related but with a very similar skull), false killer whales are long-lived (into their 60s), slow to reproduce (having one calf only every 6 or 7 years), and do not start reproducing until their teens. Thus false killer whale populations would be very slow to recover from any anthropogenic impacts. Also like killer whales, false killer whales are upper-trophic level predators, thus are likely to accumulate high levels of toxins and be impacted by competition with human fisheries.
Recent evidence indicates the insular population of false killer whales in Hawai‘i has declined dramatically over the last 20 years (Reeves et al. 2009). Five years of aerial surveys undertaken from 1993 through 2004 by Joe Mobley of the University of Hawai‘i West O‘ahu have shown a steep decline in sighting rates. Group sizes of the largest groups documented in surveys undertaken by Steve Leatherwood and Randy Reeves in 1989 were almost four times larger than the entire current population estimate (Reeves et al. 2009).
False killer whales are closely related to pygmy killer whales, short-finned pilot whales and melon-headed whales, all of which are also found in Hawaiian waters.
A number of photographs of false killer whales are below, as well as links to pdfs of a number of publications. Video clips of footage obtained using the National Geographic Crittercam system can be found at the on this page. Please note the file sizes are large so the page may take a while to load.
|
|
False killer whales with yellowfin tuna. Photo by Dan McSweeeny/Wild Whale Research Foundation |
|
A group of false killer whales from the insular population. Photo by Deron Verbeck. |
| Mother and calf false killer whale, December 10, 2008. Photo by Robin Baird. |
As part of our work to examine movements and stock structure, in July 2008 we satellite tagged seven false killer whales from the insular population. This animation shows the movements of five individuals over a 10-day period. Each step in the animation is one set of locations obtained within 10 minutes of each other, and the time intervals between steps average about one hour. The maximum time interval between steps is approximately 12 hours. Lines shown are purely to join consecutive locations for each whale and do not indicate travel routes. For more information on this work see the report on satellite tagging of false killer whales, available below. Animation produced by Damon Holzer, Northwest Fisheries Science Center.
| False killer whale with a satellite tag. Photo by Daniel Webster. We are using these tags to examine movements of both the insular and offshore populations in Hawaiian waters, in part to try to assess interactions with the long-line fishery. |
|
False killer whale carrying tuna. Photo by Deron Verbeck. |
| False killer whale carrying prey, followed by wedge-tailed shearwaters. Photo by Erin Oleson |
|
A false killer whale from the offshore population leaping while chasing prey. Photo by Robin Baird. |
| False killer whale with tuna. Photo by Annie Douglas |
| Offshore false killer whales on Jaggar Seamount. Photo by Erin Oleson. |
| False killer whale with mahimahi. Photo by Dan McSweeney. |
References on false killer whales
| False killer whale mother and calf. Photo by Deron Verbeck. |
Photos taken under NMFS Scientific Research Permits (Nos. 731-1774). All photos are copyrighted and should not be used without permission.
Video footage at the top of the page from a National Geographic Crittercam deployed on a false killer whale in Hawai'i in 2002.
Return to the Cascadia Research Hawai‘i web page