For Water Shrews, More Than 3 Hours Between Meals Could be Fatal

This tiny water shrew, the size of a thumb, is the world’s smallest warm-blooded diving species. It lives in the cool forests and montane regions of Canada and the USA. 

With a high metabolism, it needs to eat more than its weight in insects each day. It forages along riverbanks. But as colder weather approaches, and riverside insects becoming harder to find, the shrew needs to find new hunting grounds.

Fortunately, it's well adapted to the underwater world. Although it can barely see, this shrew has acute hearing and an excellent sense of smell. It can dive underwater to hunt for insect larvae and dragonfly nymphs using its sensitive whiskers to detect movement from its prey.

Air bubbles trapped in the water shrew's thick fur help it stay warm in the frigid water, allowing it to remain below the surface for 30 seconds at a time.

Click play on the video above to watch.

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