Arctic Seabirds

Predicting how climate change might affect animal species is a major concern for conservationists. The best current summary of how climate change might affect American birds is the recently-released State of the Birds, but research is still ongoing. A recent study looked at how Arctic-nesting seabirds might be affected by studying ways that birds currently die at the breeding colonies.

Mallory and two other Canadian scientists decided to combine 33 years of observation into a paper that was released in Arctic, the journal of the Arctic Institute of North America. In it, the trio track the unusual ways Arctic seabirds die and they predict that a warming climate could have serious consequences for these birds. The study is based on observations of six species of birds on 11 different seabird colonies in the eastern Arctic ranging from northern Hudson Bay to Devon Island.

Typical causes of death include crashing into each other or cliffs during heavy fog, being slammed into the ocean by Katabatic winds or, perhaps most grizzly of all, dying from a combination of heat stress and blood loss due to mosquito attacks....

Few birds winter in the Arctic because of the harsh climate conditions. But in the spring, there is a veritable explosion as millions of birds return to nest. Seabirds in Mallory's study area tend to spend the winter months floating in the North Atlantic ocean. When they return in the spring, conditions are often still very harsh. Mallory has seen fulmars and thick-billed murres incubate eggs with only their heads visible above the snow.

The preferred nesting sites of many seabirds are cliffs, which often prove to be very dangerous. Falling rocks and chunks of ice, as well as slides kill great numbers of birds. In fact, the authors cite one incident in which over 800 murres and kittiwakes died almost instantly when the ledges on which they were nesting collapsed. Mallory suspects cliffs could become unstable as temperatures rise, with more freeze-thaw action of ice.

They also predict that increased storm activity could cause additional mortality among nestlings. Dampened feathers do not insulate very well, even in slightly warmer temperatures.

The press release and abstract do not specify which species were involved, beyond the Northern Fulmar, Black-legged Kittiwake, and Thick-billed Murre mentioned in the quote above.