November 25, 2013 at 1:25 am #1271MikeKeymaster
Bird deaths puzzle Unalaska
SHEARWATERS: Captain said hail of creatures hit
his boat for up to 30 minutes.
By ALEX deMARBAN and CRAIG MEDRED
Anchorage Daily News
Published: September 1, 2006
Last Modified: September 1, 2006 at 06:13 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
Some say they may have died of hunger. Others say they’re smashing into
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,
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.
The forum ‘Strange Animal Deaths’ is closed to new topics and replies.