Researchers in Anchorage are working to crack a tough nut in the form of a beak deformity affecting a large portion of black-capped chickadees and other birds in parts of Alaska, including the Kenai Peninsula.

At the Anchorage-based Alaska Science Center, which is under the umbrella of the U.S. Geological Survey, four experts have been assigned to the Beak Deformities Project. Research on the deformities, which take several forms but are mainly categorized as an overgrowth of the beak, has been ongoing since 1999. According to the U.S. Geological Survey website dedicated to the project, Alaska has seen a dramatic uptick in the deformities in the last 10 years, most notably in black-capped chickadees.

In fact, since studies began, researchers “have … identified more than 2,000 deformed black-capped chickadees in Southcentral Alaska — the highest concentration of such abnormalities ever recorded in a wild bird population anywhere,” according to the website. The abnormalities are estimated to affect about 6.5 percent of black-capped chickadees and about 17 percent of northwestern crows, which are found throughout Alaska and the Pacific Northwest.

Like human fingernails, birds’ beaks grow continually throughout their lives and are worn down by eating and other habits. In black-capped chickadees and other birds affected by the deformity, the beaks simply grow at a rate too fast for the birds to keep up with. The deformed beaks can manifest in an overgrown top beak curved down or to the side, a beak in which the top and bottom halves are crossed, a gap between the upper and lower beak and a beak that has grown so much the tip has broken off.

While studying captive chickadees, researchers have found that rapid keratin production appears to be the main mechanism of the problem, with some of the affected birds showing keratin growth at more than twice the normal rate, said Caroline Van Hemert, one of the researchers assigned to the project.

Van Hemert said chickadees affected by the abnormal beaks are also found to have higher mortality rates, mostly because difficulties grooming and getting food makes it harder for them to survive cold weather.

“It certainly does take its toll after the more extreme weather,” Van Hemert said.

Fish & Wildlife Biologist Todd Eskelin with the Kenai National Wildlife Refuge has helped Van Hemert and other Alaska Science Center staff from Anchorage collect bird samples locally. Researchers then branched out to other birds and visited Seward, Soldotna, Valdez and Homer in addition to the refuge. They also took a look at crows on a portion of Bridge Access Road, Eskelin said.

“Basically, when they first started out they were focusing on the black-capped chickadee,” he said. “They found that the birds themselves were too small to get the materials they needed.”

Researchers have found the growth abnormalities in several other bird species, including common ravens, black-billed magpies, Steller’s jays, woodpeckers, red-breasted nuthatches and more. The overgrowth only appears to affect adult birds, which is leading researchers to believe that, if the deformities are passed down through genetics, they are latent and do not appear until the birds reach adulthood.

Possible causes include genetic abnormalities, nutritional deficiencies, contaminants, disease and parasites. Research to pinpoint the exact cause more closely is ongoing, Van Hemert said. The team is has determined that diet is most likely not a major cause for the problem and will be moving on to use genetic testing to see if the cause could be a virus. They will not be using genetics to research if the problem is actually hereditary for the moment, she said.

Since the small size of the chickadee samples made testing difficult in the past, it is pertinent for researchers to go back and re-test for certain pathogens or viruses that could be causing the deformities, Van Hemert said. None of the known viruses for chickadees have been identified as the cause, so searching for an emerging one is the next step, though Van Hemert said viruses are naturally hard to detect because they are so small.

“It’s a little bit of a needle in a haystack,” she said. “You kind of need to know what you’re looking for with a contaminant.”

The black-capped chickadee population appears fine for now, as a major problem with a bird species would result in a noticeable decline in the species, Eskelin said.

“We’re not seeing that kind of decline and there’s annual variation that would cloud any minor decline,” he said.

Things like harsh weather conditions during the bird’s nesting period and other environmental factors that change from year to year will contribute to that general population variation, Eskelin said.

The deformity does make it harder for the birds to get food. Bruce and Pamela Manley, who live on the Kasilof River, have seen the struggles caused by bad beaks firsthand.

The pair noticed a black-capped chickadee with the telltale curved beak and asked their friend and photographer, Cooper Landing resident Ben Romig, to snap a picture of it, Pamela Manley said.

“He (the bird) comes here all the time,” said Bruce Manley. “I built a little bird stand about three feet outside of our window and we have a variety of birds. … I had noticed that particular bird a few weeks ago.”

The chickadee has to turn its head sideways in order to pick up pieces of bird food that fall from the feeder onto the snow, he said. Given the bird’s handicap, it appears to be well fed and has reappeared at the Manleys’ feeder often over the last few weeks.

“I see him about every day, some days more often than not,” Bruce Manley said. “We’ve been feeding them all winter, and they’re good and healthy and fat.”

The chickadee is also able to use its deformed beak to pull pieces of food out of the actual feeder before eating it, he added. The bird enthusiast has also spotted one that appeared to have a crossed beak, but said it has not come over to the feeder like the first chickadee.

Eskelin said that while there hasn’t been a noticeable decline in the black-capped chickadee population on the peninsula, the problem is worth taking seriously.

It could be an indication of a larger, more far-reaching problem, he said.

“The one thing to take from it is really that whether it be a climate change issue, or something that’s happening in our forest … but whatever that condition is, it is a good indicator that we’re in a climate change and we should be watching for these kinds of things,” Eskelin said. “It should kind of be a red flag for people that they’re potentially serious.”

Van Hemert said climate change isn’t something her team is considering as a major factor right now.

“At this point we have no evidence to suggest that it’s related to climate change,” she said, adding that “it is concerning to see birds that are clearly struggling and unhealthy, and we don’t know why.”

To report a sighting of a bird with a deformed beak, visit the Alaska Science Center website at alaska.usgs.gov.

Reach Megan Pacer at megan.pacer@peninsula.com.