Discoveries

April 28, 2023

Big Bodies, Big Problems

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A new study discovered that the bigger the animal, the harder it is for them to stay cool while traversing large distances, New Scientist reported.

Scientists recently analyzed the maximum sustained speeds of more than 500 species of animals, ranging from insects to whales and elephants.

The study primarily focused on animals in the wild.

Their findings showed that the traveling speeds of species increased as they became larger. But these speeds leveled off and decreased once a creature’s mass reached more than 2,200 pounds.

A closer analysis suggested that the bigger animals had to slow down to avoid overheating, noting that the muscles are not very efficient.

“For every 100 joules of chemical energy that gets pumped into your muscles, 70 of those joules are just turned into heat,” explained co-author Alexander Dyer.

This overheating problem also affected swimming animals – such as whales – even though their bodies can shed heat faster in water than in air.

On the other hand, Dyer noted that smaller animals could easily lose excess heat because of their higher surface area-to-volume ratio.

The paper suggested that global warming will mean bigger problems for big-bodied animals.

“If our model is correct, larger animals will have to reduce their activity in general or they will have to shift toward more nocturnal behavior,” Dyer added.

Even so, staying cool is becoming an issue even for smaller animals as the temperatures rise, forcing some animals to develop smaller bodies to avoid overheating.

This story originally appeared in the April 28, 2023 newsletter, Change and Its Discontents.