Rising temperatures are pushing tropical bird species to the limits of what they can adapt to.

Bird populations in the tropics have dropped by roughly a third (25-38 percent) since 1980 due to intensifying heat extremes.

For some species the effects of the rapid rise in temperatures has reduced their numbers by 50%.

Researchers from the Potsdam Institute for Climate Impact Research (PIK), the University of Queensland and Barcelona Supercomputing Center (BSC), have been monitoring the decline.

 Scientist Maximilian Kotz explained:

“It’s a staggering decrease. Birds are particularly sensitive to dehydration and heat stress. Extreme heat drives excess mortality, reduced fertility, changing breeding behaviours and reduced offspring survival.”

According to the study, tropical birds are exposed to ten times the extreme heat conditions today than they were forty years ago: from an average of three days a year of extreme heat, to thirty days.

 The biggest drops in numbers were in the tropics, but nearly every region reported a loss of population abundance, with extreme heat having the greatest impact on population declines.

Tatsuya Amano from the University of Queensland commented:

“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. That might mean ex-situ conservation work – so working with some populations in other locations.”

Click on this link to access, Large reductions in tropical bird abundance attributable to heat extreme intensification, published in Nature Ecology & Evolution.