Climate change is heating things up, and new research shows that some of North America’s most cherished species can’t take the heat.
When average temperatures in a given area rise, some species move to cooler locations. This is because all species can only exist within a certain range of temperatures. If a species cannot move to more suitable areas quickly enough, or if weather patterns become erratic, the species may face a real risk of local extinction in areas that are too warm. According to a recent study published in Ecology and Evolution, University of Ottawa researchers found that some North American songbirds are becoming extinct in warmer regions of the continent.
Until now, rising temperatures due to man-made climate change had rarely been linked to local extinction rates. In fact, the distributions of many species had been holding steady at the southern edges of their ranges, even as these same species expanded the leading edge of their ranges further north.
However, new data demonstrates that as average temperatures in the southern U.S. rise, some bird populations have begun to disappear. In the north, these species are not shifting northward as quickly as they are disappearing in the south. Songbirds, such as the prairie warbler and the ethereally voiced wood thrush, are caught in a climate change vise.
The lead author of this research, Laura Coristine, a senior PhD researcher at the University of Ottawa, explains: “We thought that species might tolerate temperatures warmer than those they live in during breeding season. We were trying to understand why previous research had found that species were not moving at their southern-most edges.” What came next was surprising: according to co-author and uOttawa biology professor, Jeremy Kerr, “This is the first evidence that populations of birds at a continental scale are disappearing as temperatures rise. But we can’t detect these losses unless we examine trends over several decades using long-term field data.”
Birds captivate the attention of North Americans. Across Canada and the United States, roughly 1-in-5 people engage in birdwatching, spending enormous amounts of time on the activity. The economic benefits of this outdoor activity are huge. Birding is one of the fastest growing hobbies, and yet over 40% of Canada’s bird species are in decline. Fifteen percent of Canadian bird species are currently listed in the Species-At-Risk public registry.
Researchers have been trying to find ways to conserve species despite climate change and there is hope. Some areas have sheltered climates and species in those areas might be less affected by rising temperatures and more frequent and intense extreme weather events. The research team believes that integrating climate change policy into their scientific work could yield positive results.