By Abdullahi Lukman
Tropical bird populations have declined by approximately 25–38% since 1980 due to escalating heat extremes driven by climate change, a new study published on August 11, 2025, in Nature Ecology and Evolution has revealed.
The research, involving the Potsdam Institute for Climate Impact Research (PIK), the University of Queensland, and the Barcelona Supercomputing Centre (BSC), highlights that some species have experienced population drops exceeding 50%.
Lead author Maximilian Kotz, a guest researcher at PIK and BSC, emphasized the severity of the findings: “Birds are particularly sensitive to dehydration and heat stress. Extreme heat drives excess mortality, reduced fertility, changing breeding behaviours, and lower offspring survival.”
The study shows tropical birds are now exposed to ten times more extreme heat events than 40 years ago — from an average of three days per year to 30.
Researchers used a combination of observational data and climate models to isolate the effects of rising temperatures and precipitation changes on bird populations globally.
While tropical regions faced the most significant losses, nearly all parts of the world reported declines, with heat extremes emerging as the leading driver.
The findings also suggest that in many tropical areas, heat stress is now a more significant threat to bird populations than deforestation.
“This helps explain unexplained bird losses in intact tropical rainforests in the Amazon and Panama,” noted the team.
Co-author Tatsuya Amano added that conservation efforts must now also include strategies for species vulnerable to heat, such as relocating populations or using ex-situ conservation.
Kotz concluded by underscoring the root cause: “Ultimately, our emissions are at the heart of this issue. We need to be bringing them down as fast as possible.”
