2007-08-30, Beavers 海狸（在线收听） |
| We are here in the wilderness in the Rocky Mountains, observing nature's impressive architects and engineers: beavers. By creating this pond they are preventing soil from being washed away and they are creating a place where new plants and insects can flourish. Beavers think ahead and secure their foods supply long before they'll need it. They drag these branches into the water where they will stay fresh and accessible during the winter freeze. Flash forward to the winter freeze, when the frigid temperature has turned the mud and sticks into a secure shelter for the beavers. Each dwelling house is a single beaver family. Yep, with a mom and dad and, did I mention beavers mate for life? And each home has an elegantly designed passageway to the lake. Beavers are North America's largest rodent. And they are the only ones with skin flaps behind their teeth that allow them to hold branches without swallowing water. Notice how neatly the beaver eats, stripping the bark by turning the branch like an ear of corn. They are strict but voracious vegetarians and can even digest the soil lodes that most mammals just can't handle. Flash forward again to the following spring, and spring has sprung a leak in the dam. So dad stays with the young ones while mom and her elder son fix it up. This is lucky for all the other animals around because virtually, the entire ecosystem is dependent on the dam and the resulting pond. Wouldn't it be great if we could all be as industrious and efficient as the eager beavers? |
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