Animals’ body sizes shrinking from climate change, study finds

Climate change is having profound effects on earth and its ecosystems. From the fossil record, it is known that during past periods of global warming, both marine and land-based animals have become smaller.

PHYS.ORG: ‘University of Cape Town (UCT) researchers have collected clear evidence—over a 23 year period between 1976 and 1999—that climate change is shrinking animals’ body sizes. Associate Professor Res Altwegg and Dr. Birgit Erni from the Department of Statistical Sciences, together with colleagues, studied changes in the weight of mountain wagtails, a type of bird, along the Palmiet River in Westville, KwaZulu-Natal.

Climate change is having profound effects on earth and its ecosystems, and during the past 100 years, global temperatures have increased by close to 1 °C. From the fossil record, it is known that during past periods of global warming, both marine and land-based animals have become smaller. And scientists have proposed that contemporary warming could lead to smaller animals, but so far, evidence supporting this has been scarce…

To investigate this idea and whether it could be true, the research team looked at a group of wagtails living along the Palmiet River. What they found supports the idea that climate change can shrink Earth’s animals. “All else being equal, larger animals can tolerate cold conditions better than smaller animals, so one could expect that a warming climate is relatively more advantageous for smaller animals,” said Professor Altwegg…

“Other studies have shown that animals are shrinking in various places around the world,” Professor Altwegg said. “But, they generally didn’t have the detailed data to show that temperature actually affected the animals directly by changing their ability to survive.” Overall, their results support the idea that shrinking body size is a response to climate change’. SOURCE…

RELATED VIDEO: