Climate Change Has Laid Waste to Tropical Bird Populations: Study

“It’s a staggering decrease,” said Maximilian Kotz, of the Potsdam Institute for Climate Impact Research and the Barcelona Supercomputing Center, who led the study, in a statement. “Birds are particularly sensitive to dehydration and heat stress. Extreme heat drives excess mortality, reduced fertility, changing breeding behaviours and reduced offspring survival.”

The study, published in Nature Ecology & Evolution, used a “climate attribution framework” to pin bird population declines on the various factors at play. They found that warmer temperatures have caused a decline of between 25 and 38 percent across the tropical regions of the world, with losses accumulating since 1950. In other words, compared to a counterfactual world that did not have any climate change occurring, we have that many fewer tropical birds on this warmer planet.

“Rising temperatures are really pushing species out of the ranges that they’ve naturally adapted to – and in a very short amount of time,” Kotz said. Other studies have documented large-scale bird declines even in places where deforestation has not been a problem — a neotropical forest in Panama, an untouched lowland Ecuadorian forest — though they did not generally pinpoint specific reasons for those declines. Outside of that brand of human intervention, the global version altering temperatures and precipitation patterns is the obvious villain.

“On the conservation side, this work tells us that in addition to protected areas and stopping deforestation, we urgently need to look into strategies for species who are more vulnerable to heat extremes to maximise their adaptation potential,” said co-author Tatsuya Amano, of the University of Queensland.

Beyond the immediacy of conversation work, the solution here, unsurprisingly is to fix it all:  “Ultimately, our emissions are at the heart of this issue,” Kotz said. “We need to be bringing them down as fast as possible.”