Global warming is causing animals to ‘change shape’

Climate change is not just a human problem; animals must also adapt to it. Some “warm-blooded” animals change shape and have larger beaks, legs, and ears to better regulate their body temperature as the planet warms. Bird researcher Sara Ryding from Deakin University in Australia describes these changes in a review published on September 7 in the journal Trends in ecology and evolution.

“Most of the time when climate change is covered in the mainstream media, people ask ‘can humans overcome this? Or “what technology can solve this?” “. It is high time that we recognize that animals must also adapt to these changes. , but it’s happening on a much shorter timescale than what would have happened for most of evolutionary time, ”says Ryding. “The climate change we have created is putting tremendous pressure on them, and while some species will adapt, others will not.”

Ryding notes that climate change is a complex and multifaceted phenomenon that occurs gradually, so it is difficult to identify a single cause of the change in shape. But these changes have occurred over large geographic areas and across a wide range of species, so there isn’t much in common apart from climate change.

A strong change in shape has been particularly reported in birds. Several species of Australian parrots have shown, on average, a 4-10% increase in beak size since 1871, which is positively correlated with summer temperature each year. The black-eyed juncos of North America, a type of small songbird, showed an association between increased beak size and short-term extremes in temperatures in cold environments. Changes have also been reported in mammalian species. Researchers reported increases in tail length in wood mice and increases in tail and leg size in masked shrews.

“The increases in appendage size that we are seeing so far are quite small (less than 10%), so the changes are unlikely to be immediately noticeable,” says Ryding. “However, important appendages such as the ears are expected to increase, so we may end up with a live Dumbo in the not-so-distant future.”

Next, Ryding intends to study shape change in Australian birds firsthand by 3D scanning museum bird specimens from the past 100 years. This will allow his team to better understand which birds are changing the size of their appendages due to climate change and why.

“Shape change doesn’t mean animals are dealing with climate change and everything is fine,” says Ryding. “It just means that they evolve to survive there, but we don’t know what the other ecological consequences are of these changes, or that all species are able to change and survive.”