Scientists baffled by whale attacks on porpoises

摘要

Scientists in Vancouver are grasping for answers to explain why southern resident killer whales, a group of fish eaters that prefers chinook salmon, have also been observed toying with harbour porpoises before leaving them dead. Two cases were observed in October, in Washington state and British Columbia's (BC) Strait of Georgia.rnSpeculation has ranged as to a possible explanation. There is a possibility that killer whales might see the porpoises as an opportunity for a playful 'cat and mouse game1. Or, female killer whales may be trying to prop up the porpoises as if they were their own young. The porpoises can ultimately succumb to shock, exhaustion, injury or drowning.