"Mad Cow"

this is fairly widespread in the wild now...

http://biology.usgs.gov/status_trends/mammals.html

Chronic wasting disease (CWD) Chronic wasting disease

another type of black bird found in large no's in Alaska...

Anchorage Daily News

http://www.adn.com/news/alaska/story/8145569p-8037818c.html

Bird deaths puzzle Unalaska

By ALEX deMARBAN and CRAIG MEDRED
Anchorage Daily News

Published: September 1, 2006
Last Modified: September 2, 2006 at 01:43 AM

More than 1,600 sea bird carcasses have washed onto Unalaska shores over the last two days in a mysterious die-off that scientists are scrambling to understand.

Some say they may have died of hunger. Others say they're smashing into boats.

Maybe it's both, some scientists said.

Several hundred black, gull-like shearwaters died after flying into a crabbing boat that steamed through the early morning darkness in Unalaska Bay on Wednesday morning, said Forrest Bowers, a fisheries biologist for the state Department of Fish and Game in Unalaska.

The captain of the boat walked into Bowers' office that day to report that a hail of shearwaters struck his boat for up to 30 minutes, Bowers said. The crew pitched the dead and dying birds overboard, the captain said, according to Bowers.

Bowers would not release the captain's name, saying he requested anonymity.

The captain reported that other boats were in the area and may also have been bombarded by the sea birds, Bowers said.

It's happened before in Unalaska, but usually not in such big numbers, Bowers said.

Seabird specialist Art Sowls at the Alaska Maritime National Wildlife Refuge in Homer said he had neither heard nor read of massive numbers of shearwaters dying in a collision with a ship or ships.

"That's not something that would have come to mind," said the biologist, who has been called in to consult on the deaths.

"There are some species that actually are attracted to lights on boats," including shearwaters, he said. He's heard of shearwaters hitting structures in Hawaii but not boats, he said.

Still, he added, a massive death toll due to collision is not impossible.

"Shearwaters can be in flocks of over a million birds," Sowls said, and the birds go through a molting process that limits their ability to fly. Most should have just finished molting.

"They can fly," he said, "but they are somewhat immobile."

Given just the right circumstances, he said, maybe a ship or ships could steam into a massive flock that just couldn't get out of the way fast enough.

"That would be amazing if that was what caused it," he added.

Reid Brewer, a local marine biologist with the University of Alaska Fairbanks, said he counted just over 1,600 carcasses on the pebbled shores near homes in Unalaska and along beaches outside the Aleutian island community.

The birds don't appear thin and aren't oiled, he said. Some had necks twisted at odd angles, as if they had smashed into something, he said.

Seabird authority David Irons of the U.S. Fish and Wildlife Service in Anchorage had a similar reaction to the news of masses of dead shearwaters. Starvation, he said, would be a far more likely cause for the deaths than a collision.

"They don't normally run into ships," Irons said.

It is possible, however, that birds weakened by starvation could have struck boats, he added, or that the carcasses washing ashore could be a combination of birds that starved and birds that hit ships.

"Shearwaters are the most abundant bird out in the Bering Sea," Irons said. Given their sheer numbers, it would not be surprising to witness a seemingly massive die-off due to starvation or disease.

The population is so large the census is a broad estimate from 9 million to 20 million birds.

Irons said he expects that the dead birds will be checked for avian flu -- the hot disease of the day -- but everyone involved with this die-off thinks that it is an unlikely cause.

Sowls said the Fish and Wildlife Service is coordinating a carcass retrieval to get birds delivered to laboratories for testing. That's the only real way to determine the cause of the die-off, he said.

On Thursday, Sowls was also trying to contact people along the Aleutian Islands and out in the Pribilof Islands to see if they had spotted unusual numbers of dead shearwaters washing ashore -- an event that would likely coincide with a natural die-off.

"It's not unusual to have birds dying," he said, but to have hundreds or thousands of them dying at once is unusual.

Both Irons and Sowls said they expect the total number of dead birds is much larger than the 1,600 carcasses that have been found.

"Typically, you find a fairly small percentage of the ones that die," Sowls said.

We began research in 1999, and have since identified nearly 1,500 deformed Black-capped Chickadees in south-central Alaska—the highest concentration of such abnormalities ever recorded in a wild bird population anywhere!  More recently, rapidly increasing numbers of other species, including Downy Woodpeckers, Northwestern Crows, Steller’s Jays, and Black-billed Magpies have also been reported with beak deformities by biologists and local residents throughout the state.

Although we do not yet know the source of this widespread problem, we continue to investigate potential causes, including environmental contaminants, nutritional deficiencies, and disease.  Nearly all of the species affected are year-round residents, and we suspect that factors responsible for this cluster of deformities may be unique to Alaska and the Pacific Northwest.  We are currently pursuing additional studies to determine where these deformities are occurring and why.  Reports from the public help us to determine where and how many birds are affected.  If you see a bird with a deformed beak, please contact us.

Black-capped Chickadee, USGS photo