Dolphin Attacks On Harbor Porpoises
Although herding may be confined to the coast of Australia, biologists have reported that other types of aggressive dolphin behavior are more widespread than many people believe. Only bottle-nosed dolphins, however, have been observed to show these mysteriously violent tendencies. In the late 1990's, researchers in Virginia and Scotland were surprised by the discovery of several instances of extreme violence by bottle-nosed dolphins.
Some of the first evidence of dolphin brutality began washing up on the shores of Moray Firth, a large bay on the northeast coast of Scotland, in 1990. Researchers found hundreds of harbor porpoise carcasses on the beach. The bodies did not look badly injured, but when scientists performed autopsies, they discovered that all the bodies had sustained serious injuries. Most of the dead porpoises had fractured bones, ripped tissue, and bruised organs.
Researchers originally theorized that boat propellers or fishing nets might have been responsible for the death of the porpoises. But in 1994, researchers discovered a dead porpoise with fresh bite marks. Scientists measured the marks and discovered that they exactly matched the spacing of the teeth on an adult bottle-nosed dolphin. Why the dolphins were killing porpoises was a mystery, since the two animals do not compete for the same fish for food.
Find Your Perfect Pet
Comments ( )