The hundreds of bird species making these incredible migrations are under pressure now. A major study by the Audubon Society in 2019 examined 140 million records, including observations from citizen scientists, of 604 North American bird species to assess their risks under different degrees of global warming [PDF]. The results showed two-thirds—389 species—were at risk of extinction from climate change. While indigo buntings, for example, face less danger than other species, its grassy habitats could be reduced by increased wildfires and urbanization, and spring heat waves could affect their chicks’ survival. Under a scenario where the average global temperature warms by 3°C—which could occur as soon as 2080—the buntings’ range would shift north, losing ground in the South and Midwest and extending into Ontario and Quebec.
2 of 12