First Observations of Feeding on Thresher (Alopias vulpinus) andHammerhead (Sphyrna zygaena) Sharks by Killer Whales (Orcinus orca)Specialising on Elasmobranch Prey

摘要

Killer whale (Orcinus orca) predation on elasmobranchs (sharks and rays) is not often reported. In New Zealand waters, killer whales captured and ate thresher (Alopias vulpinus) and smooth-hammer-head (Sphyrna zygaena) sharks. Both species were not reported previously as prey of killer whales. These observations help support the idea that elasmobranchs are a main prey type for New Zealand killer whales; ten species of elasmobranchs are now recorded as prey for this population.