By Joanna Thompson, Intern, Audubon Magazine on August 13, 2021. This is a shortened version. Click here for the full article.
Every April, like clockwork, hundreds of Caspian Terns descend upon an abandoned concrete factory in West Seattle and nest on its flat, sandy roof. Ordinarily the birds raise their chicks on this faux beach in relative peace. But not this year. On June 28, as temperatures broke records across the Pacific Northwest, scores of tern chicks leapt from the roof in a desperate search for relief from the heat….
…In the end, 52 tern chicks were taken to PAWS Wildlife Center in Lynwood, Washington, for rehabilitation. About half did not survive, but thanks to the efforts of PAWS and other on-site rescuers, 25 young terns were successfully reintroduced to the colony.
Extreme heatwaves across the Pacific Northwest and southwestern Canada disrupted countless nesting birds this year. In addition to the terns, baby swallows, sparrows, and raptors also flooded into PAWS and other wildlife rehab facilities after jumping from their nests. “The center was very, very busy during that heatwave,” says PAWS wildlife naturalist Jeff Brown. PAWS received 45 songbirds and 31 raptors, including 11 Cooper’s Hawks and eight Bald Eagles…
….Ecologists expect to see chick mortality events like these with increasing frequency—especially among species adapted for life in cool conditions—as a result of climate change coupled with growing habitat loss. Extreme heat events, currently estimated to occur once a millennium, might occur every 5 to 10 years under a 2-degree-Celsius warming scenario, according to an analysis by World Weather Attribution, an international scientific collaboration that has developed methods to connect extreme weather with climate change. The heat would have been “virtually impossible without human-caused climate change,” the report concluded. ..
…Birds aren’t the only ones in danger. Over the course of three days, 13 people lost their lives to hyperthermia in Seattle alone, and more than 1,500 were hospitalized with heat-related ailments across the state of Washington, according to the Seattle Times. A New York Times analysis suggests hundreds more people across Oregon and Washington likely died.
This year’s extreme heat probably did not have an effect on the birds at a population level; they’ve evolved to miss a breeding season here and there. However, a regular onslaught of heatwaves during successive nesting seasons, on top of habitat and climatic changes around nesting grounds, could result in shrinking local populations, says Blair Wolf, a biologist at University of New Mexico.
