In this April 1, 2009, photo provided by the USGS Alaska Science Center shows a black-capped chickadee with a deformed beak in Anchorage, Alaska. Researchers are hoping they've found what's causing beaks of some bird species to grow twice as fast as normal. The disease is called avian keratin disorder. Affected birds grow beaks that are freakishly long and that sometimes curve up or down. (Handel Colleen/USGS Alaska Science Center via AP)

In this April 1, 2009, photo provided by the USGS Alaska Science Center shows a black-capped chickadee with a deformed beak in Anchorage, Alaska. Researchers are hoping they've found what's causing beaks of some bird species to grow twice as fast as normal. The disease is called avian keratin disorder. Affected birds grow beaks that are freakishly long and that sometimes curve up or down. (Handel Colleen/USGS Alaska Science Center via AP)

Researchers link virus to birds with deformed beaks

  • By Dan Joling
  • Monday, October 24, 2016 10:49pm
  • News

ANCHORAGE — Biologist Colleen Handel saw her first black-capped chickadee with the heartrending disorder in 1998.

The tiny birds showed up at birdfeeders in Alaska’s largest city with freakishly long beaks. Some beaks looked like sprung scissors, unable to come together at the tips. Others curved up or down like crossed sickles.

Handel, a U.S. Geological Survey bird specialist, was sure the cause of avian keratin disorder would be found quickly: contaminated birdseed, a poison targeting spruce bark beetles, maybe some sort of bacterium or fungus.

Years went by. She found herself losing sleep over a mysterious ailment afflicting 6.5 percent of southcentral Alaska’s black-capped chickadees and 17 percent of the area’s northwestern crows, more than 10 times what is normally expected in a wild bird population. Distorted beaks were spotted in lesser numbers of jays, woodpeckers and nuthatches — 24 species in all.

Eighteen years later, after many possible causes were ruled out, Handel and other scientists from California and Alaska who tested beaks of affected birds found a previously unknown virus in every one.

“It’s the strongest lead that we’ve got so far,” Handel said.

Bird beaks have inner layers of bone covered by an outer layer of keratin, the same stuff as fingernails. The disorder affects the outer layer, stimulating the keratin to grow twice as fast as normal.

Chickadees look fragile but are one of the few birds to stay through cold Alaska winters. In the dead of winter, the small songbirds can lose 10 percent of their body weight overnight and must eat constantly during short daylight hours. Extended beaks get in the way.

“They can’t eat enough during the daylight hours to survive overnight, because they’re metabolizing the fat they put on during the day,” Handel said. “The other thing is that the poor little guys can’t preen their feathers very well. You can imagine trying to comb your hair with a pair of 3-foot-long chopsticks.”

They end up with dirty, matted plumage and feathers that no longer provide insulation. “They’ve lost their little down coats for winter,” Handel said. Some don’t survive.

Over nearly two decades, researchers pursued multiple paths of research. Last year, Handel and fellow USGS researcher Caroline Van Hemert published a study showing an environmental contaminant, organochloride compounds, were found in affected birds. But the amount was small and there was no obvious source, such as the selenium from agricultural drainage that caused beak deformities in California or PCB and other contaminants that affected birds in Great Lakes states in the 1970s.

The mysterious condition appeared only in birds 6 months or older, so it did not seem to be a birth defect. It affected chickadees, which live in the forest, and northwestern crows, which live in intertidal zones. But both birds are social, so it was conceivable they could transmit disease among their species.

The potential breakthrough came when researchers at the California Academy of Sciences in San Francisco offered to apply advanced DNA and RNA sequence technology to bird beak samples.

Early in 2012, disease ecologist Maxine Zylberberg had an “aha!” moment. She found the birds had RNA of a virus in the same family that causes the common cold and polio in humans and foot-and-mouth disease in cattle.

The previously unknown virus was in every sample of deformed chickadee beaks and in two samples of chickadees that did not have distorted beaks.

“After that it was a lot of validation, going through and testing more individuals and seeing, ‘Is this true?’” Zylberberg said.

Researchers are careful to say the virus — named Poecivirus after the black-capped chickadee genus — has not yet been nailed down as the cause of distorted beaks.

“It could be that birds who have this disease are more susceptible to this common virus,” said Zylberberg, now at the University of California, San Francisco and lead author of the study published July 26 in mBio, a journal of the American Society for Microbiology.

To validate their findings, scientists will grow the live virus in laboratory conditions. They also will work to determine whether the virus is in other bird species and how it is being transmitted.

In Britain, significant numbers of blue tits, a close relative of black-capped chickadees, have been observed with beak deformities. In all, 36 species with deformed beaks have been documented there.

“Now, with this genetic test, we have a way to see, ‘Do those birds have the same virus or not?’” Handel said.

More in News

Signs direct voters at the Kenai No. 3 precinct on Tuesday, Oct. 5, 2021. (Camille Botello/Peninsula Clarion file)
Signs direct voters at the Kenai No. 3 precinct for Election Day on Tuesday, Oct. 5, 2021. (Camille Botello/Peninsula Clarion)
Local candidates report support from state PACs

Labor unions and the National Education Association are among the groups putting money into Kenai Peninsula state election races

Signs and examples on the recycling super sack at the Cook Inletkeeper Community Action Studio show which plastics are desired as part of the project in Soldotna, Alaska, on Aug. 11, 2022. Plastics from types 1, 2, 4 and 5 can be deposited.(Jake Dye/Peninsula Clarion)
Local nonprofit accepting plastics for synthetic lumber project

The super sack receptacles can be found on either side of Soldotna

This July 28, 2022, photo shows drag queen Dela Rosa performing in a mock election at Cafecito Bonito in Anchorage, Alaska, where people ranked the performances by drag performers. Several organizations are using different methods to teach Alaskans about ranked choice voting, which will be used in the upcoming special U.S. House election. (AP Photo/Mark Thiessen)
Groups get creative to help Alaska voters with ranked voting

Organizations have gotten creative in trying to help voters understand how to cast their ballot, as the mock election featuring drag performers shows

A school bus outside of Kenai Central High School advertises driver positions on Wednesday, Aug. 10, 2022, in Kenai, Alaska. (Ashlyn O’Hara/Peninsula Clarion)
Staff shortage, gas prices change school bus routes

The changes do not apply to the district’s special education students

The cast of “Tarzan” rides the Triumvirate Theatre float during the Independence Day parade in downtown Kenai, Alaska on Monday, July 4, 2022. (Camille Botello/Peninsula Clarion)
The show goes on as Triumvirate seeks funding for new theater

The troupe has staged shows and events and is looking to debut a documentary as it raise funds for new playhouse

Aaron Surma, the executive director for National Alliance on Mental Illness Juneau and the Juneau Suicide Prevention Coalition, leads a safety plan workshop Tuesday night hosted by NAMI and the Juneau Suicide Prevention Coalition. The workshop was a collaborative brainstorming session with Juneau residents about how to create a safety plan that people can use to help someone who is experiencing a mental health or suicide crisis. (Clarise Larson / Juneau Empire)
Study shows a rise in anxiety and depression among children in Alaska

Increase may indicate growing openness to discussing mental health, according to experts

Alaska Lieutenant Governor Kevin Meyer addresses election information and misinformation during a press conference on Wednesday, Aug. 10, 2022. (Screenshot)
With a week to go, officials work to clear up election confusion

Officials provided updated ballot statistics, fielded questions from reporters and clarified misconceptions about the current election cycle

COVID-19. (Image courtesy CDC)
State reports 21 new COVID deaths; cases down from last week

20 of the reported deaths took place from May to July

A closeup of one of the marijuana plants at Greatland Ganja in Kasilof, Alaska, as seen on March 19, 2019. (Photo by Brian Mazurek/Peninsula Clarion)
Assembly streamlines process for marijuana establishment license applications

License applications will now go straight to the Kenai Peninsula Borough Assembly for consideration

Most Read