Endotherms, commonly called warm-blooded animals, have changed the shape of their bodies over the past century to keep themselves cooler in response to rising global temperatures.
Many animals have body parts that stick out, such as ears, beaks, limbs and tails. at Deakin University in Australia and her colleagues have found that a variety of animals have been responding to increasing global temperatures by increasing the size of these appendages.
鈥淚 would classify the changes as not something that might be visibly obvious,鈥� says Ryding. 鈥淵ou might not hold a bird from the 1800s in your hand and then hold a bird from the 2000s and see an immediate difference. But the reported estimates of increases that we found are still functionally important.鈥�
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The team combined the findings of previous studies that looked at appendage size in various animals across the globe, including Australian parrots and thrushes, Galapagos finches, Chinese bats and European mice. Changes included larger bills in bird species like the crimson rosella (Platycercus elegans), larger wing size in bats like the great roundleaf bat (Hipposideros armiger), and increased tail length in mammals like the masked shrew (Sorex cinereus).
Larger appendages are one way an animal can increase its surface area relative to its body volume which, for an endotherm, makes it easier to lose excess body heat.
Some species, such as the fruit bat Leschenault鈥檚 rousette (Rousettus Leschenaultii), didn鈥檛 display these increases in appendage size. This may be because appendages in these species are used in important ways by these animals that constrain their size, says Ryding.
鈥淭here鈥檚 enough evidence there to say that there might well be something interesting going on here, but I think it鈥檚 too early to say if it鈥檚 a general phenomenon that鈥檚 occurring in response to climate change,鈥� says at University College Cork in Ireland. 鈥淲e need more studies of different types of animals from different places.鈥�
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