'Splooting' Squirrels Seen Around San Francisco During California Heat Wave

San Francisco's Squirrels have been spotted "splooting," or lying splayed out on the ground on their bellies, as they try to survive the California heat wave.

Temperatures in San Francisco have reached a scorching 105 degrees, and while humans have been able to retreat to their air conditioned homes, squirrels in the area can only resort to "splooting" to keep cool.

Alison Hermance, a worker at WildCare in San Rafael told SFGate that her animal hospital had "been receiving lots of calls about hot animals, including concerns about squirrels 'spread out flat.'"

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A file photo of a squirrel laying on its belly. This "splooting" is a way animals stay cool in hot weather. iStock / Getty Images Plus

"If you see a squirrel lying down like this, don't worry; it's just fine," tweeted the NYC Parks Department in August, in response to concerned residents who had seen squirrels laying on their bellies during a heat wave in New York last month.

"On hot days, squirrels keep cool by splooting (stretching out) on cool surfaces to reduce body heat. It is sometimes referred to as heat dumping."

Animals, including humans, need to regulate their temperature to avoid heat stroke or hypothermia. Humans have a variety of ways of cooling ourselves down in hot weather, ranging from sweating, vasodilation (blood vessels widening) in the skin, and our body hair laying flat against our skin to prevent hot air being trapped.

Animals covered in fur can't sweat, however, meaning that they need other ways of staying cool. Many mammals pant, evaporating heat away via the dampness inside their mouths, while others rely on behavioral cooling, finding shade, or laying their bodies against a cool surface, which is also known as "splooting."

"The squirrel is putting as much of their body surface as possible in contact with a cooler surface, frequently on concrete or pavement that's been in the shade, Charlotte Devitz, a biologist and Ph.D student studying squirrel behavior at the University of Minnesota, told CNN.

"[This is] also seen in other mammals. It's just gained a lot of visibility because a lot of people see it and become worried when they see squirrels on their belly."

Other animals have also been known to "sploot," including bears, dogs, cats and otters.

These heat responses in the animals of California come during an intense heat wave, caused by a powerful "heat dome" over the state. This kind of scorching heat is thought to be one symptom of encroaching climate change, which is expected to increase the frequency of extreme weather events. While this will have damaging effects on humans, the change in climate will also affect millions of animals around the world.

"[We have received] young squirrels coming in with heat stroke," Hermance said about this week's heatwave, as well as "calls about hot deer, and about birds literally falling on their sides, panting with the heat."

According to a paper published in The Proceedings of the National Academy of Sciences in 2020, one-third of the Earth's animal and plant species may be extinct by 2070 if current greenhouse gas emissions trajectories continue.