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Killer whales preying on gray whale migration
But biologists think attacks may be a good sign
April 28, 1997
Web posted at: 12:10 p.m. EDTFrom Correspondent Susan Reed
MONTEREY, California (CNN) -- In the springtime, gray whales that have been calving and wintering in the Gulf of California journey north to summer and feed in the bountiful waters of the Gulf of Alaska.
(1.4 M/35 sec. QuickTime movie)
But the annual migration is proving unusually harrowing this year.
Killer whales are preying on gray whale calves in what biologists believe is unprecedented fashion.
"This is the most this kind of thing has happened since anyone can remember," says biologist Nancy Black.
In one incident, videotaped by Black and her associates, three killer whales attacked and killed a gray calf and began to feed on it while 12 others killer whales circled hungrily nearby.
According to Black, as many as 15 to 25 killer whales work together when attacking the huge grays. Even the gray calves are significantly larger than killer whales, so the smaller whales harass the calves until they tire.
They then hold them underwater until they drown, and spend the next five to seven hours eating them.
Biologists think attacks may be a good sign
Black and her team have counted five such attacks in the last week and a half and estimate that at least that many more took place elsewhere along the California coast over the same period.
The biologists suspect that the unusual frequency of the attacks may, in a curious way, be a good sign.
They think that the gray whale, which was once an endangered species and has been protected for years by federal law, may be nearing its original population and may be competing with other whales for food.
The killer whale, being at the top of the marine food chain, is apparently doing its part to restore the ecological balance.
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