[Animals] Animals Are Shape-Shifting in Response to a Warming World

[Wassim]

t the South African nature preserve where Mira Warrington and colleagues study Cape ground squirrels (Xerus inauris), the maximum daily temperature has increased by about 2.5 °C in just 18 years. The animals have evolved a quiver of tactics to tolerate the region’s sweltering heat, says Warrington, a conservation ecologist at the University of Manitoba. Sprawling flat on the ground in a pose called splooting, for example, helps the animals shed heat from their less furry undersides. The squirrels also take shady respites under their bushy tails, which they curl above their heads like tiny parasols. When it’s really hot, the fossorial mammals retreat to their burrows to cool off. But Warrington warns that, even with all these options for keeping cool, “still they could be at the limits of their tolerance” due to such a rapid climactic shift.

That intense pressure could be why their bodies have begun to change shape, Warrington says. She found that, over the course of just under two decades, the squirrels’ already incredibly large hind feet, which may help dissipate heat, have grown relative to their body sizes by about 11 percent. Meanwhile, their spine lengths have become about 6 percent shorter.

And the Cape ground squirrel isn’t the only animal that appears to be shape-shifting in response to climate change. As scientists accumulate more evidence that many species’ bodies are undergoing subtle changes over a relatively short period of time, it remains unclear whether their adaptations can keep ahead of spiking temperatures—and how close they may be to a breaking point.

https://www.the-scientist.com/news-opinion/animals-are-shape-shifting-in-response-to-a-warming-world-70869