CRITTERS OF NORTH IDAHO: Water shrew
It may surprise you how many kinds of animals adapt to a life more dependent on the water than their cousins. Sea otters, as their name implies, spend all of their lives at sea unlike their cousins, the river otters. Polar bears are the only species of bear classified as a marine mammal because they rely on the ocean for food and livelihood. The proboscis monkey of Southeast Asia is more aquatic than any other primate, using its partially webbed feet to dive underwater.
In a similar fashion, a number of species of shrews have adapted to a semi-aquatic lifestyle while the rest of their family lives on land. Native to streams and other bodies of water in Alaska, Canada, and the northern United States, Idaho included, the American water shrew (Sorex palustris) is one of them.
As far as appearances go, these little guys don’t stand out too much. They typically weigh no more than 18 grams and measure 5.1-6.7 inches from snout to tail; males are usually larger and heavier than females. Though their fur is usually colored black or gray-black on top with a silvery-gray underbelly, the color appears darker in the winter and more brown in the summertime. On land, you may have difficulty telling the water shrew apart from other shrews.
However, if a snake, weasel, a bird of prey such as an owl or a hawk, or some other predator attacks, this shrew jumps into the nearest body of water and dives. The water shrew can spend around 45 seconds underwater, and it’s such a tiny animal that the air bubbles that become trapped in its thick fur, as well as its foot and toe fringes, enable it to skitter along the water’s surface!
When not fleeing from predators, the tiny water shrews are almost always keeping up with their surprisingly big appetites, which require them to eat 0.95 grams a day. Water shrews have to eat a lot because their metabolic rate is so high that they must eat at least once every three hours or die from starvation. Something tells me we won’t see water shrews taking part in a weight loss program at the gym anytime soon!
While they occasionally snack on snails, slugs, land insects, earthworms, vegetation, and even mice and small salamanders, water shrews find most of their food, as you might expect, underwater. Their hunting expeditions usually last between 31 and 47 seconds. What if it’s wintertime and the water is frigid? No problem! Remember those air bubbles that become trapped in the water shrew’s fur when it dives? They also help reduce heat loss by 50 percent. As they dive, people studying water shrews have heard them making constant high-pitched noises.
Scientists think that the high-pitched noise is because the water shrews are using echolocation — that is, they make noises which bump into nearby objects and travel back to the shrew’s ears — much like dolphins and bats. The favorite prey of the water shrew is aquatic insect larvae and nymphs of stoneflies, crane flies, caddisflies, mayflies and even the occasional small fish. Once prey is caught, the little creature will hold it between its front legs and proceed to tear it to pieces with its sharp teeth.
After some 30 minutes of activity, the water shrew spends another hour or so resting up for its next hunting expedition.
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WATER SHREW
HOMESCHOOL PROJECT
WORD GAME
The picture above, of a shrew, describes different areas of the body. Take each group of words (phrase) and see how many words that you can make. You can use the letters multiple times in each group, but not more letters than are in the the phrase. The words do not have to be related to the shrew.
As you can see in the example I have used the letter “e” multiple times. The phrase, “shrews are tiny” only has two e’s, but I have used the letter “e” five times.
EXAMPLE
“Shrews are tiny”
1. Renew
2. We
3. New
4. He
Email me your word list. You will end up with five groups. The person with the most words in each group will be announced on the 16th of April 2019. The DEADLINE for SUBMISSION is the 12th of April 2019.
Here is an example of what each group should look like.
Five long toes with claws
1.
2.
3.
...
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Project provided by Angel Dominiq
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