Climate Crisis, Biosphere & Societal Collapse

Sloths, the famously slow-moving yet adorable creatures native to Central and South America, could face extinction by the end of the century due to climate change.

Researchers investigating how sloths respond to rising temperatures have found that the animals' slow metabolism and limited ability to regulate body temperature may leave them unable to survive in a warming world—especially for populations living in high-altitude regions.

"Despite being iconic species, comprehensive long-term population monitoring simply hasn't been conducted at a scale that reflects the true challenges sloths face," lead researcher Rebecca Cliffe told Newsweek. "However, from our 15 years of working with sloths in Costa Rica, we are very concerned. In areas where sloths were once abundant, we have observed their populations completely disappear over the past decade."

The study, published in PeerJ Life & Environment, focused on two-fingered sloths inhabiting both lowland and highland environments in Costa Rica.

"Sloths are uniquely vulnerable to rising temperatures due to their physiological adaptations," Cliffe said. "They survive on an extremely low-calorie diet, so conserving energy is critical for them.

"One key way they do this is by not actively regulating their body temperature like most mammals do—temperature regulation is an energy-intensive process."

A major concern is that sloths' slow digestion rates—up to 24 times slower than similar-sized herbivores—make it difficult for them to increase food intake to meet rising metabolic demands.

This slow metabolic rate, combined with their minimal energy-processing capacity, means that sloths cannot easily balance the increased energy requirements brought on by higher temperatures.

Published study : https://doi.org/10.7717/peerj.18168