Lone Researcher Documents Arctic Warming's Toll on Seabirds

For nearly five decades, George Divoky conducted a remarkable, largely solitary study on Cooper Island, Alaska, documenting a colony of Mandt's black guillemots. His research, which began in 1972, initially focused on birds nesting under U.S. Navy debris left from the Korean War. This unique situation allowed for detailed observations of nearly every nest.

The colony, which started with 10 breeding pairs, expanded to around 200 pairs by 1989. Divoky meticulously recorded breeding success, banding individual birds to gather extensive data. His annual summer visits, often spent living alone in a tent, created one of the longest continuous records of an Arctic bird population.

As the Arctic warmed, sea ice retreated further from Cooper Island during breeding seasons. This change made Arctic cod, a crucial food source for chicks, less accessible. The guillemots increasingly relied on less nutritious fourhorn sculpin, leading to slower chick growth and higher mortality rates.

By 2017, the colony had fallen to 85 breeding pairs, with reproduction levels insufficient to sustain the population. Increased polar bear and horned puffin predation also contributed to chick deaths. In response, Divoky installed predator-resistant nest cases in 2011, though the colony's decline continued, highlighting the profound impact of climate change on this Arctic ecosystem.