By Joe Liebezeit
Earth Day this year has been dedicated to presenting “the face of climate change.” Nowhere is this face more on view than in Arctic Alaska. Like the birds I study, I migrate to this fantastic landscape every summer.
At 231,000 square kilometers, Arctic Alaska is larger than Minnesota and encompasses most of the northern portion of the state and the entire Arctic coastal plain.
During the summer, the coastal plain transforms itself from a sub-zero inhospitable place to a vast productive wetland. Millions of migratory birds from all over the world – including waterfowl and shorebirds – return there to breed on the tundra: timing their nesting activities with melting snow and a bountiful flush of insects.
Working as a conservation biologist for the past 12 years, I’ve witnessed firsthand the growing impacts of a warming planet in Arctic Alaska – where climate change is occurring at a rate more accelerated than anywhere else on this planet.
As the trend toward higher spring temperatures, milder winters, and lingering autumns continues, there is tremendous uncertainty about how species like migratory birds will respond to a much warmer year-round landscape in the long-term.
In the past year, more than 80 science experts were involved in assessing 54 breeding bird species in Arctic Alaska. We found populations of nine bird species that were vulnerable to climate change impacts.
Two in particular – the gyrfalcon and common eider – are likely to be “highly” vulnerable, while seven other species would be “moderately” vulnerable to climate change. We also documented five species whose numbers may actually increase as the climate warms.
The assessment will help conservation scientists unravel the mystery behind why a changing climate impacts some species more than others.
In the short-term, it appears that some species may be “winners” and others “losers” with respect to their ability to adjust their behavior to cope with climate change impacts.
Our ongoing research provides clear evidence that at least some bird species are nesting earlier as temperatures increase. Such a response to climate change may temporarily benefit certain birds by creating a sustained nesting period that gives them more time to raise chicks.
The long-term prospects are far less certain. Scientists worry that the nesting cycles of birds that rely upon the emergence of insect larvae to feed their chicks could become unsynchronized, leaving hatchling chicks with little food to nourish their rapidly-growing bodies.
Over time, some tundra breeding habitats may be encroached upon by shrub and tree species from the south. For shorebirds in particular, loss of crucial coastal habitats from sea-level rise and increasing human activities could severely impact populations at migration staging areas.
It is unclear exactly how climate change will transform tundra habitats, but it is clear there will be dramatic changes. A drying trend, which is already occurring in some parts of the Arctic, could parch wetlands essential to nesting bird species for both shelter and foraging.
Climate change is also influencing the predator-prey relationship between larger shorebird species and the red fox– an Arctic predator invading from the south that outcompetes the smaller Arctic fox.
We have seen more and more red foxes every year and fewer of the Arctic variety in the past decade. Bird species like the American Golden-Plover can successfully defend their nests from Arctic fox, but would have a harder time against the larger red fox.
While climate change challenges habitats and wildlife in Arctic Alaska, patient and careful observation helps us prioritize conservation planning efforts and safeguard breeding bird and other critical wildlife populations.
One thing is clear. Birds act as sentinels, and the climate changes confronting them now will in time express themselves in the lower latitudes where most of us live.
Joe Liebezeit is the Arctic birds project leader for the Wildlife Conservation Society.