How animals beat the heat in Alberta and elsewhere
Naturalist Brian Keating explains how critters survive extreme temperatures
From wallowing in mud to creating their own breeze, animals find creative ways to survive a heat wave.
Calgary naturalist Brian Keating has traveled to some of the hottest places on the planet and explained to The Homestretch on Monday just how animals stay cool when high temperatures hit.
Elephants, for example, will go for swims to cool down, but their physiology helps, too — specifically, those large ears.
"Scientists tell us that the blood that goes … back into the body after going through the ear, especially when the elephant's ear has been wet, it will go down into the body seven degrees cooler," said Keating.
Migrate, hibernate or tolerate
In the winter, animals in Alberta have three strategies to survive the cold: migrate, hibernate or tolerate.
"Those three strategies still apply even for heat, but, of course, there's variations," said Keating.
Summer temperatures can encourage "vertical migration" up the slopes of mountains. There's about a 3 C drop for every 300 metres in elevation gain, so animals can reach cooler temperatures and sometimes even snow up in the high country.
Instead of hibernating — which happens in the winter — some critters escape hot and dry weather with an equivalent state called estivation. The Richardson's ground squirrel is one.
"The males have already done their important job of breeding earlier on in the season. So they've been busy fattening up," said Keating. "As soon as they're physiologically ready, they're going to go [underground] just to escape the liability of hanging out and about. And so they go into a state of lower body temperature and slower breathing, just like hibernation."
Last, and most common, is simply tolerating the hot weather. This includes behaviour like staying in the shade, being active in the early morning or the evening, or being nocturnal.
Turtles and even freshwater fish will go into deeper, cooler waters during intense heat, whereas the spadefoot toad in southern Alberta is a classic example a nocturnal creature, said Keating.
"They've got a tremendous toleration of desiccation; they'll dry out almost completely," he said. "They operate at night to get away from the heat and they operate after the rains. In fact, they do something called explosive breeding during the rainy time, and then they stay dormant for the rest of the year."
Heat stress getting worse
As average summer temperatures rise, even animals that are adapted for the heat have trouble.
"Heat stress is is real out there and it's getting worse," said Keating. "Researchers are looking at heat related local extinctions or the disappearance of species in certain parts, especially in areas like deserts, where already it's harsh, and you make it a little bit more harsh and it becomes virtually unbearable."
Unlike us humans, most animals can't sweat to cool off. Instead, they pant — even birds like the mourning dove, which lives in Alberta. But panting, explained Keating, makes an animal lose a lot of water, and it's worse in higher temperatures.
A 2019 study in California, for example, found that mourning doves require up to 30 per cent more water to keep cool compared with a century ago.
"The only way they get their moisture, if they can't find a pond, is to catch and eat more insects," said Keating. "That's where they get their moisture. And, of course, that requires more energy, and the cycle continues."
How can you can help? Leave birdbaths or some kind of water outside in your yard to help the animals cope with intense summer heat.
For more fascinating stories about Alberta's wildlife from naturalist Brian Keating, visit his website and check out these stories:
With files from The Homestretch