Their beaks are elongated, curved or do not meet in the middle, impeding birds’ attempts at foraging, preening and keeping themselves warm and well fed, especially in winter.
It’s a problem showing up in more and more birds, with Alaska as the apparent epicenter, and studies are under way to determine the cause. Grappling with another problem, other researchers in the state are studying how climate change may be affecting the availability of prey for migratory songbirds. Both groups recently received grants from different branches of the federal government to conduct their research.
Photo: Courtesy U.S. Geological Survey
A normal bill on a black-capped chickadee.
A $90,631 grant from the U.S. Environmental Protection Agency (EPA) to the nonprofit Alaska Songbird Institute’s Alaska Swallow Monitoring Network will fund research into climate change affects on birds. The grant, awarded in May, provides for community volunteers in Native villages and elsewhere to collect, analyze and present ecological data on climate change impacts to Alaska’s tree swallows, which breed here and spend winters in warmer climes. The institute works to conserve Alaska’s boreal songbirds through ecological education and research via a research and education project at Creamer’s Field Migratory Waterfowl Refuge, a 2,000-acre state wildlife refuge in Fairbanks.
Swallows are aerial insectivores, “a group of birds that are declining rapidly [in population], especially in northern ecosystems,” according to the institute’s Swallow Ecology Project. Alaska is the northern extent of the breeding range of tree swallows, “making it an ideal location to look at their response to changing environmental conditions.”
In 2016, the institute will train interns, middle- and high-school students, and community volunteers—teachers, older residents and Alaska Native culture-bearers who carry indigenous knowledge about Alaska’s climate history—to monitor existing swallow nests and establish and monitor additional swallow nesting sites.
“The chronology and success of each nest will be monitored,” the project website states. Adult birds will be banded “to look at longevity and site fidelity.” The diversity and abundance of aerial prey will be assessed throughout the nesting season. “Together, over time, these data help us learn more about swallows in the far north.”
Volunteers will present their findings to the community and at professional conferences.
In other research, biologist Colleen Handel of the U.S. Geological Survey’s (USGS) Alaska Biological Science Center has compiled reports of deformities in 28 bird species in Alaska, including year-round residents like crows, jays, magpies, nuthatches, ravens and woodpeckers.
“Bill deformities in migratory species, including American tree sparrows, Lincoln sparrows, ruby-crowned kinglets, orange-crowned warblers, and dark-eyed juncos, have also been recorded,” reports the Cornell University Lab of Ornithology, which collaborates with the USGS on studies of bird health and population.
“Every migratory bird observed with a bill deformity has been a juvenile bird,” meaning the birds had not yet been outside of Alaska when the deformity was observed.
Handel received 2,153 reports of chickadees with deformed bills—those reports pertained to 1,441 individual birds—in Alaska from November 1991 through May 2005. DNA tests showed that chickadees with bill deformities had a significantly greater amount of DNA damage than normal chickadees.
“This damage could be caused by exposure to contaminants or by disease,” the Cornell website reported. “Handel was unable to find evidence of disease.”
According to Cornell, a calcium deficiency could be causing the deformities; a few of the chickadees in Handel’s study had broken or deformed legs, a symptom of calcium deficiency. And this is where changes in food may come in.
“The short winter days in Alaska might result in an insufficient amount of Vitamin D, which would cause a reduction in the amount of calcium chickadees can absorb in winter,” Cornell reported. “Furthermore, a lack of natural foods could force chickadees to become overly dependent on seeds, which, in addition to reducing the calcium intake chickadees normally get from insects, could exacerbate a calcium deficiency since the high fat content of seeds could interfere with calcium uptake in the body.”
Other researchers have shown that cormorants exposed to low levels of PCB and kept in captivity for two weeks without natural daylight developed bill deformities.
“The potential of a combined effect between PCBs and calcium deficiency will be tested with captive birds in the next phase of Handel’s research,” Cornell reported.
All told, EPA funded 35 grants from organizations in 26 states. Grants range from $36,000 to $192,000, for a total of more than $3.3 million. Since 1992, EPA has distributed between $2 million and $3.5 million in grant funding per year, for a total of approximately $68 million supporting more than 3,600 grant projects. The competitive grants program “supports environmental education projects that increase public awareness about environmental issues and provide participants with the skills to take responsible actions to protect the environment,” the EPA said.