Feeling the heat: fungal infections reduce tolerance of heat

Researchers examined frogs infected with a microscopic skin fungus and found it reduced their heat tolerance up to four degrees Celsius.

“We also found that numerous other animal groups become more sensitive to heat when infected with parasites and pathogens. This suggests that this phenomenon might be widespread,” lead author Sasha Greenspan said. The team’s research has been published in the international journal Scientific Reports.

JCU’s Professor Ross Alford said that in frogs and other animals that depend on external sources for body heat, behaviours that raise body temperature, such as basking in the sun, may directly kill parasites or strengthen the host’s immune system.

“This helps animals to cope with infections. It’s similar in effect to when humans get a fever to beat the flu. But, increased sensitivity to heat from infections may discourage these protective behaviours, tipping the balance in favour of the parasite,” he said.

Brett Scheffers, a co-author on the study and assistant professor of wildlife ecology and conservation at the University of Florida Institute of Food and Agricultural Sciences, said scientists have seen an increase in animal and plant diseases.

“We have a lot to learn about how this will impact wildlife as the climate continues to change. Considering that the climate is becoming warmer and more extreme, climate change and new diseases might work together to drive species to extinction, but in a way that isn’t always obvious — such as changing the animal’s tolerance of heat,” he said.