A Rüppell’s fox is seen at the Sheikh Butti bin Juma Al Maktoum Wildlife Centre in the United Arab Emirates. The animal can live in areas with almost no water, such as central Saudi Arabia.

“Time is running out”

So are heat-adapted species better suited to survive an increasingly hot planet, or are they just as out of luck as the rest of us?

It depends, researchers say. (Read how extreme heat can trigger die-offs for some animals in the American West.)

As a general rule, the smaller, more widespread, and less complex an organism, the quicker it can adjust to change.

That’s why a species like deer mice would have more opportunities to evolve enhanced adaptions to heat than, say, endangered elephants, says Martha Muñoz, a biology professor at Yale University in Connecticut. Larger populations often provide greater genetic variation for tinkering.

Secondly, evolution requires time. A bacterium can reproduce six times a day, creating plenty of quick turnover. Blue whales, on the other hand, can take up to 15 years to reproduce.

Some species can change their behavior when faced with hotter temperatures—though even that has consequences.

Muñoz and colleagues found that Anolis lizards living on the edges of Caribbean forests where they can move between warmer and cooler spots—like hiding under boulders in the heat of the day—did not bother changing their metabolism or other physiological factors when temperatures increased. That ultimately diminished their future generations’ ability to do so.

Because deer mice (pictured, captive Florida deer mice) breed rapidly, they can possibly evolve adaptations to extreme heat more quickly than animals with longer life spans.

Their forest brethren, however, increased their baseline heat tolerance, and were better able to survive. This evolutionary phenomenon even has a name: the Bogert effect.

She has also found, as with acorn ants, that some species can evolve quickly. In one study, the montane horned lizard in Mexico increased its heat threshold by about 1.8 degrees Fahrenheit following a year of heat waves. 

But despite such remarkable adaptations, Muñoz warns they’re not nearly quick enough to keep up with the rate of our planet’s warming.

These animals are “existing on borrowed time, and time is running out.”

Dromedary camels (seen in the Arabian Desert) can extract water from the humid air through specialized nostrils.