Tiny Water Shrews Are the “Cheetahs of the Wetlands”

They look like long-nosed mice but are not rodents. They can hunt and smell underwater, their favorite place to find food. No bigger than a human thumb, they are the smallest diving mammal on Earth.

These are water shrews, what PBS Nature calls “cheetahs of the wetlands.” And they are hungry.

“Water shrews have the highest metabolism of any diving mammal. They seldom go more than a few hours without a meal and this shrew hasn’t eaten all morning. The edge of the stream provides some rewards, but he’ll need more than an insect carcass to satisfy his appetite…”

“Because of his poor eyesight, he must rely on a complex hunting strategy. He scans the surface to detect the slightest break in the water. Then he forages along the bottom, trying to shake loose his prey. When his long whiskers detect movement, he gives chase.

“Crayfish can be elusive and they’re also half his size. But with reflexes 10 times faster than our own, he eventually outpaces them.”

These small American water shrews are related to moles and hedgehogs, all insectivores that might hunt for insect larvae and nymphs, arthropods, and earthworms. Water shrews also have the advantage of foraging underwater for 45 seconds or longer, and might snack on a tiny fish.

The video clip is from PBS Nature’s Niagara Falls,

“Fun” fact: Eurasian water shrews have venomous saliva.

Watch these videos next:
• How does the Great Diving Beetle hunt underwater?
• The six-spotted fishing spider hunts and eats fish
• Nature’s Scuba Divers – How Beetles Breathe Underwater
• The Star-Nosed Mole and its extraordinary nose