Lethal heat in the tropics: climate change is decimating birds without respite
The tropics, considered the greatest reservoir of biodiversity on the planet, are witnessing how their winged richness is eroding with each episode of extreme heat. International researchers have analyzed over 90,000 bird records and have concluded that climate change is already causing a drastic decline in their populations, with no evidence of recovery.
The invisible impact of extreme heat
The study, published in [journal], shows that the frequency of days where the temperature exceeds 99% of historical values has multiplied by ten in the last 40 years in the tropics. These heatwaves affect much more than the average temperature rise or changes in rainfall: they are the main factor behind the decline of birds.
New international study links extreme heatwaves to the loss of 25–38% of tropical birds since 1950.
An accumulated and irreversible decline
Between 1950 and 2020, they fell by up to 38% due to extreme temperatures. The analysis, led by Maximilian Kotz (Potsdam Institute and Barcelona Supercomputing Center), rules out direct human pressure as the main cause in these areas: heat alone explains the decline. Furthermore, the effects are cumulative: once populations decrease after an extreme episode, no subsequent recovery is detected.
Differences between regions and species
The impact varies with latitude: in subtropical areas, a reduction of 3–5% is observed, while in high latitudes, no significant effect is detected. Resident and migratory birds show similar patterns, although species in tropical dry forests are especially vulnerable.
“One of the most striking parts of our research is that, even in areas where deforestation is not affecting birds, there are threats due to the intensification of temperature extremes caused by humans”: Maximilian Kotz, study author.
Implications for conservation
The authors warn that most climate models have ignored the frequency of extreme events, focusing only on annual averages. This work demonstrates that this approach is insufficient: heatwaves are now an immediate and growing threat to tropical biodiversity.
An urgent call to action
The decline already coincides with independent observations in forests such as those in Panama and the Amazon, even in protected areas. For researchers, the message is clear: reducing greenhouse gas emissions is essential, but so is integrating the growing threat of heat extremes into the planning of natural reserves and conservation strategies.
