BANDON, Ore. — Hundreds of the seabirds known as rhinoceros auklets have washed up on the southern Oregon coast, and scientists haven't settled on an explanation for their deaths.
The birds seem to be in good shape off California and Washington, a researcher said.
"The questions in my mind are: Is this something that's widespread in Oregon? Is it a freak event like a storm, or something that's going to last longer?" said seabird researcher Julia Parrish, an associate professor of biology at the University of Washington.
Explanations include a storm that killed lots of birds as they were gathering for breeding season and warming ocean waters that are inhospitable to the bird's food chain.
Parrish is executive director of the Coastal Observation and Seabird Survey Team, which gets reports from beach watchers. She said there were no reports of an increase of dead auklets elsewhere, and populations at seabird colonies off San Francisco look normal at the start of breeding season.
Beach observers say the birds started washing up this month off the southern Oregon coast, and hundreds of carcasses, as many as 20 to 30 per mile, were reported last week.
Rhinoceros auklets live most of their lives at sea. They are scrappy, constant flyers and look like little footballs, almost pointy on the ends, black on top and white underneath.
Underwater, they swoop to depths of 200 feet, snapping up small fish. In breeding season, they grow a horn of sorts, hence the rhinoceros name.
Biologists estimate there are about 1,000 rhinoceros auklets breeding in colonies off the coast of Oregon each spring. California supports about 2,000 breeders, and 60,000 are off Washington, with hundreds of thousands even farther north, said Jan Hodder, associate professor of marine biology at the Oregon Institute of Marine Biology.
Countless thousands likely winter in the waters off Oregon.
In spring 2005, beach watchers found dead seabirds, mostly cormorants and murres, at the rate of 8 per mile from central California to British Columbia.
Scientists blame a warmer ocean and too little plankton and other food because of a lack of spring and summer ocean upwelling.