Wildlife biologists Rob Kaler of the U.S. Fish and Wildlife Service and Sarah Schoen of the U.S. Geological Survey examine body parts of a common murre during a necropsy on Friday, March 11, 2016, in Anchorage, Alaska. Kaler and Schoen are among scientists attempting to find out the reason for a massive common murre die-off in the North Pacific that began one year ago. (AP Photo/Dan Joling)

Wildlife biologists Rob Kaler of the U.S. Fish and Wildlife Service and Sarah Schoen of the U.S. Geological Survey examine body parts of a common murre during a necropsy on Friday, March 11, 2016, in Anchorage, Alaska. Kaler and Schoen are among scientists attempting to find out the reason for a massive common murre die-off in the North Pacific that began one year ago. (AP Photo/Dan Joling)

Scientists continue researching seabird death mystery

  • By Dan Joling
  • Saturday, March 12, 2016 9:32pm
  • News

ANCHORAGE — The common murre on Sarah Schoen’s examination table lived a short, hungry life.

Measurements of its beak and leg indicated it hatched in June. Its stomach and breast showed how it died. The 3-inch-long stomach was empty, and the pectoral muscles that powered its wings, allowing it to “fly” underwater after forage fish, were emaciated.

“As the bird starves, the body eats the muscle for energy,” Schoen said. “The muscle becomes more and more concave.”

Schoen, a wildlife biologist for the U.S. Geological Survey, and Rob Kaler, a biologist for the U.S. Fish and Wildlife Service, on Friday performed necropsies on common murres, part of an effort by dozens of scientists to explain the massive die-off of common murres that began one year ago.

Common murres are one of the northern hemisphere’s most common seabirds. The Alaska population is estimated at 2.8 million out of a world population of 13 to 20.7 million birds. Awkward on land, common murres can dive to 600 feet hunting fish or krill.

Die-offs have occurred before but not on this magnitude. Common murres routinely live 20-25 years but have a metabolism rate so high that they can use up fat reserves and drop to a critical threshold for starvation, 65 percent of normal body rate, in three days of not eating.

Abnormal numbers of carcasses, all showing signs of starvation, began washing ashore on Alaska beaches in March 2015. Numbers spiked to alarming levels in early winter.

The confirmed carcass count is now up to 36,000, Schoen said. That’s far higher than previous common murre die-offs and many beaches have not been surveyed.

New common murre carcasses continue to be recorded, most recently on Kodiak, Alaska Peninsula communities and the Pribilof Islands.

“The ravens and eagles make it easy to see that birds are continuing to die and get washed up,” Kaler said. The scavengers eat the dead murres.

No one is offering an estimate of the total deaths. In previous die-off, researchers estimated that only about 15 percent of carcasses reach shores, which means the total may be in the hundreds of thousands.

The USGS’s National Wildlife Health Center in Madison, Wisconsin, is testing murres for signs of disease or parasites. Though the murres appear to have starved, researchers wonder if something caused them to quit eating or to be less successful funding food.

Schoen and Kaler were looking for broad, general information about body conditions.

They extracted samples of liver, which can indicate what the bird ate a week before it died, and muscle, which can indicate what it ate in the last month. They took feather samples for isotope analysis regarding diet.

Sudden diet changes could be telling. If they were eating at one level of the food web, and a regular food source became unavailable, it could provide insight into the deaths, Schoen said.

Some details are emerging.

Schoen in January necropsied 61 birds found in Prince William Sound. Most were birds under 2 years old and 77 percent were female. Female deaths are significant because of the possible effect on the overall population.

The sampled birds also were heavier than birds sampled in a 1993 die-off, Schoen said.

“So it doesn’t look like just starvation is killing them,” Schoen said. “It looks like there’s something else that could be tipping them over the edge.”

That reason could be a toxin birds ingested from tainted algae. The reason could be severe winter storms that kept weakened birds from feeding. Or it could be something unknown.

Federal agencies don’t have dedicated funding to solve the common murre mystery but will continue investigating as time allows. Schoen and Kaler said they hope to continue the sampling work with carcasses collected from other areas of Alaska.

More in News

The Kenai Peninsula College main entrance on Aug. 18, 2022, in Soldotna, Alaska. (Jake Dye/Peninsula Clarion)
Chiappone and Dunstan to speak at the KPC Showcase

Kenai Peninsula College continues its showcase with two new speakers this week and next

U.S. Rep. Mary Peltola, D-Alaska, talks about issues of concern regarding the proposed merger of supermarket chains Kroger and Albertsons during a floor speech in the House chamber on Wednesday. (Screenshot from official U.S. House of Representatives video feed)
Begich leads in early results, but Alaska’s U.S. House race won’t be immediately decided

About 245,000 ballots had been counted by 11:32 p.m., and Peltola trailed by about 5 percentage points

The Alaska governor’s mansion on Wednesday. Gov. Mike Dunleavy is considered a contender for a post in Donald Trump’s second presidential administration. (Mark Sabbatini / Juneau Empire)
Election summary: Trump wins, GOP takes over U.S. Senate, Alaska may get new governor

Begich and repeal of ranked choice voting narrowly lead; GOP may lose control of state House.

Nesbett Courthouse in downtown Anchorage on Oct. 7, 2024. (Yereth Rosen/Alaska Beacon)
Voters line up at the polling site at Anchorage City Hall on Nov. 4, 2024. City Hall was one of the designated early voting sites in Alaska’s largest city. It is not a designated site for Election Day voting. (Yereth Rosen/Alaska Beacon)
Alaska Republicans lose two seats in state House, increasing odds of leadership switch

Rural Alaska precincts had reported few results by 11:30 p.m. Tuesday night.

Donald Trump won or was leading as of Wednesday morning in all seven swing states in the 2024 presidential election. (Doug Mills / The New York Times)
Donald Trump returns to power, ushering in new era of uncertainty

He played on fears of immigrants and economic worries to defeat Vice President Kamala Harris.

A voter is handed as ballot at Woodworth School in Dearborn, Mich., on Tuesday, Nov. 5, 2024. One of the most consequential presidential elections in the nation’s modern history is well underway, as voters flocked to churches, schools and community centers to shape the future of American democracy. (Nick Hagen/The New York Times)
Trump verges on victory, picking up Pennsylvania

Donald Trump has captured Pennsylvania, the biggest prize of the seven battleground… Continue reading

Signs and supporters line the Kenai Spur Highway in Kenai, Alaska, on Tuesday, Nov. 5, 2024. (Jake Dye/Peninsula Clarion)
Update: Unofficial results for the 2024 general election

Preliminary, unofficial election results as of 9:55 p.m.

Poll worker Carol Louthan helps voters submit ballots at the Soldotna Regional Sports Complex in Soldotna, Alaska, on Tuesday, Nov. 5, 2024. (Jake Dye/Peninsula Clarion)
Update: Bjorkman, Ruffridge, Elam and Vance lead in election night results

Several residents said that they came out to vote because they knew this election was “a big one.”

Most Read