Slowness helps makes sloths masters of disguise. They’re so slow algae grows on their fur, which may help them blend into the tree canopy, although, Cliffe explains, they face few predators in the wild since “big cats and harpy eagles are extremely rare now.” Still, “they move slowly to evade predators sight. Therefore camouflage is extremely important to them,” she says. (Read about the moths that live on sloths.)
Torpid turtles and sluggish slugs
The leisurely lifestyle can be dangerous. Without the ability to outrun predators, many slower animals have adaptations that make them difficult or unpleasant to pursue or eat.
There’s not much better defense than having armor fused to your body, like the iconically slow turtles and tortoises. ”Having that kind of architecture doesn’t make you speedy,” says Jeffrey Lovich, a reptile expert at the U.S. Geological Survey’s Southwest Biological Science Center. The desert tortoise, for example, has an average speed of 0.2 mile (0.3 kilometer) per hour. But the excellent protection on these herbivores has helped them survive for over 200 million years in the slow lane.
Mollusks, the group to which slugs and snails belong, have made it 550 million years without a speeding ticket. Traveling by muscular contractions called pedal waves makes slugs and snails pretty slow. Like turtles, snails rely on a defensive shell. Being nocturnal and having a mucus that smells and tastes nasty helps provide some additional safety.
“Generally animals get fast evolutionarily if they are pursued or if they pursue,” Chris Barnhart, a biologist at the Missouri State University, explains via email. “Fast” is a relative term, though. The Rosy Wolf snail follows the mucus trail of other snails and slugs and whizzes along at about 0.001 mile (0.0016 kilometer) per hour. The scent of these predators, Barnhart notes, will make other snails try to “run” and amp up their speed a bit (this poor fellow didn’t make it).
Shell-less slugs may compensate for their their lack of armor with an even “more copious and stickier defense mucus,” according to the Carnegie Museum of Natural History. The goo may work—domestic cats and dogs tend to avoid slugs.
Slow-moving sea life