Cheetahs Become More Nocturnal in Extreme Heat, Study Finds

Cheetahs typically hunt during the day. But when temperatures rise, they adjust their schedules to become more active at dawn and dusk—which puts them at greater risk of conflicts with larger predators like leopards and lions, a new study has found.

The findings, published Wednesday in the journal Proceedings of the Royal Society B, offer a possible glimpse into the future if global temperatures continue to rise because of human-caused climate change.

Cheetah numbers are already declining—an estimated 6,500 adults remain in the wild—and these big cats are listed as “vulnerable” by the International Union for Conservation of Nature. But amid global warming, their situation could become “really critical,” says Bettina Wachter, a Namibia-based biologist at the Leibniz Institute for Zoo and Wildlife Research who was not involved in the new study, to Christina Larson of the Associated Press (AP).

“It’s predicted to become much warmer in this part of Africa where cheetahs live, in Botswana, Namibia and Zambia,” she tells the publication.

Cheetahs, lions, leopards and African wild dogs inhabit the same regions and sometimes eat the same foods. One way these species have evolved to co-exist peacefully with each other is to hunt at different times of day. Leopards and lions are on the night shift, while cheetahs and African wild dogs primarily search for prey during daylight hours.

But, periodically, the animals’ schedules overlap. And when that happens, cheetahs are generally forced to give up their catches to the larger cats. Leopards and lions typically prefer fresh meat and will hunt down prey themselves. But they’re also opportunistic feeders, so if they come upon a cheetah feasting on a recent kill, they won’t hesitate to take it for their own, per the AP.

Scientists were curious to know how climate shifts might be affecting these dynamics, so in 2011 they attached GPS tracking collars to 53 total predators, including leopards, cheetahs, lions and African wild dogs. For eight years, they noted the animals’ locations and their hours of activity. Then, they analyzed this data against maximum daily temperatures.

On days when temperatures skyrocketed—topping out at around 113 degrees Fahrenheit—cheetahs shifted their hunting hours to become more nocturnal, the researchers found. This shift increased their overlap with other big cats by nearly 16 percent.

“We think it’s just too hot for them to be active during the daytime hours, and so they become more nocturnal, the same way people do in some countries where they try to avoid the midday heat,” says study co-author Kasim Rafiq, a wildlife ecologist at the University of Washington, to ABC News’ Julia Jacobo.

The new study did not involve recording actual encounters between cheetahs and other big cats, so the researchers can’t say for sure whether this increased overlap is contributing to more conflicts. They’d like to try to answer that question next by using accelerometers—which measure how much and how fast animals move—and audio-recording devices.

Cheetahs aren’t the only animals shifting their behavior because of climate change. Other studies have found that female Arctic ground squirrels are leaving their hibernation burrows earlier in the spring, that African wild dogs are giving birth three weeks later than normal and that puffins are changing their diets to the detriment of their chicks, for example.

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Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.