Frogs that can take the heat have better chance of fighting extinction

Amphibians that can tolerate higher temperatures are likely to fare better against disease, habitat loss and climate change, according to researchers.

FIU biologist Maureen Donnelly contributed to two studies on the ability of frogs and amphibians to survive challenges brought on by a changing planet — challenges she said could lead to extinction.

The strawberry poison frog is one of the amphibians Maureen Donnelly studies in the tropics.

“Amphibians regulate their body temperatures through behavior. Unlike mammals and birds, who regulate their body temperature metabolically, frogs have to move from place to place to find temperatures and environments that suit them,” Donnelly said. “When you’re dealing with small animals such as frogs and salamanders, they have a complex thermal landscape because they can use small retreats to retreat from dangerously high temperatures.”

One of the world’s deadliest wildlife pandemics is caused by the fungus Batrachochytrium dendrobatidis, or Bd. In a study published in Ecology Letters, researchers found amphibians that can tolerate higher temperatures are at lower risk of being infected by the fungus. This is because Bd thrives in cooler environments, and frogs with low tolerance to heat are essentially stuck in the same thermal environment as the fungus. Bd is responsible for dramatic population declines and extinctions in more than 500 amphibian species throughout the Caribbean, Central and South America, North America and Australia. There is no effective measure for controlling the disease in the wild, according to Donnelly, an expert in tropical amphibians and reptiles.

In a study published in Conservation Biology, the researchers examined how changing temperatures can alter the amount of habitat suitable for tropical amphibians in Costa Rica. They found the loss of thermally suitable habitats brought on by climate change may outpace habitat loss caused by forest clearing. According to the researchers, the combined effects of land use and climate change may result in the complete loss of thermally suitable habitat for some species that are most sensitive to temperature increases.

“Amphibians are facing an unprecedented global extinction crisis,” Donnelly said. “Amphibians eat insects that carry diseases, including the Zika virus, that directly impact human health. We don’t know what will happen when we take out an entire lineage that’s lived longer on this planet than the dinosaurs. We’re the stewards of the planet, and it’s our responsibility to take care of all species.”