New publication: Reeves, R.R., S. Leatherwood, and R.W. Baird. 2009. Evidence of a possible decline since 1989 in false killer whales (Pseudorca crassidens) around the main Hawaiian Islands. Pacific Science 63:253-261. The abstract is below. A pdf can be downloaded from www.cascadiaresearch.org/robin/falsekillerwhale.htm
From Randy Reeves: Steve Leatherwood died 12 years ago, at the age of 53, leaving behind not just an aggrieved family and a host of cherished friends and colleagues, but also a great deal of "unfinished business." A small item in the last category was a set of observations made during a one-off aerial survey project in Hawaii. Next to other, weightier projects, the task of bringing this one to the publication stage kept getting put off. In fact, both Steve and I had basically forgotten about it by the time he died. When, about a year ago, Robin raised the idea of publishing our findings, I was able to locate only the data sheets and a handwritten narrative describing methods and results of the 1989 surveys. The photographs, which would provide very useful confirmation of both the species and the numbers, are still missing. Maybe some day they will surface. Meantime, we welcome this chance not only to complete this little item of unfinished business, but also to remind others in the field of marine mammal science and conservation of Steve's many contributions to it.
The American Cetacean Society published a tribute issue to Steve in their journal Whalewatcher in 1999. They have made pdf copies of the articles from that issue available on their web site free of charge - http://www.acsonline.org/publications/whalewatcher/ww-catalog1994.html Abstract Recent evidence indicates there is a small, demographically isolated, island-associated population of false killer whales (Pseudorca crassidens) around the main Hawaiian Islands. Although it is known that false killer whales in Hawai'i are sometimes killed or seriously injured in the Hawai'i-based long-line fishery, it is not known whether such interactions have resulted in a reduction in population size, or whether other factors have been negatively influencing population size. We report the results of an aerial survey in June and July 1989, the purpose of which was to obtain a minimum count of the number of false killer whales around the main Hawaiian Islands. The false killer whale was the third most commonly seen species of odontocete off the island of Hawai'i during the survey, representing 17% of sightings. Groups of more than 300 individuals were seen on three different days, with minimum counts of 380, 460, and 470 individuals in these groups. The encounter rate, relative species ranking, and average group size from the 1989 survey were all substantially greater than those from more recent aerial and ship-based surveys. The largest group observed in 1989 (470) contained almost four times as many whales as estimated for the entire main Hawaiian Islands from recent aerial surveys (121 individuals, CV = 0.47) or mark-recapture analyses (123 individuals, CV = 0.72). Therefore, the population of false killer whales around the main Hawaiian Islands may have declined substantially since 1989. The cause or causes of such a decline are uncertain. ======================================================== Robin W. Baird, Ph.D. Research Biologist Cascadia Research Collective 218 1/2 W. 4th Avenue Olympia, WA 98501 USA Fax 1-360-943-7026 e-mail: rwbaird@cascadiaresearch.org www.cascadiaresearch.org/robin/hawaii.htm www.cascadiaresearch.org/robin/kwindex.htm