Matkln et al.: Ecotypic variation and predatory behavior among Orcinus orco off the eastern Aleutian Islands 



81 



— Transient killer whale encounters 

 BERING SEA 



y *«i 



-^'#L, Alaska Peninsula  



/ 



PACIFIC OCEAN 



164°W 

 L_ 



5 10 20 



' ' '  I I I 1..^ 



Nautical Miles 



•^^■^ 



Alaska 



Figure 2 (continued) 



that were common to both regions and time periods, 

 although the regions are geographically adjacent (Figs. 1 

 and 2). In the second year, 2004, in False Pass-Unimak 

 Island, 74 whales were identified and 45 (60%) had 

 been photographed the previous year. In the Unimak 

 Pass-Umnak Island surveys in both 2003 and 2004, only 

 about 28% of the whales identified had been previously 

 photographed in the region. 



Offshore killer whales Only one encounter, which 

 occurred in the eastern Aleutians (10 July 2003), was 

 with killer whales identified by genetic and acoustic data 

 as the offshore ecotype. We photographed 54 offshore 

 killer whales in this encounter, although not all whales 



present were photographed. A total of 44 of these offshore 

 whales had been previously photographed off British 

 Columbia, Washington State, and Kenai Fjords, Alaska, 

 and 10 had not been previously photographed (Ellis'). 



Description of the marine mammal prey base 



Although we did not measure the actual abundance of 

 potential marine mammal prey, we recorded sightings 

 of all marine mammals and calculated average group 



^ Ellis, G. 2005. Unpubl. data. Fisheries and Oceans 

 Canada, Pacific Biological Station, 3190 Hammond Bay 

 Road, Nanaimo, British Columbia, Canada V9T 6A7. 



