Bears eat human food when they can get some.But in a new study, the more human food 30 female black bears ate, the less time those bears were likely to spend hibernating(冬眠）．In turn,bears that hibernated less were likely to score worse in a test for aging.
The new research grew out of an earlier project to see what wild black bears across Colorado were eating, says Jonathan Pauli, a researcher from the University of Wisconsin-Madison.
Another researcher Rebecca Kirby checked diets of hundreds of bears across the state when she was a Ph.D.student. She found that hunters there were not allowed to set out bear bait（诱饵）。That means the animals' way to get human food is mostly through finding human food themselves.
When bears eat more human food, their bodies pick up higher levels of a form of carbon known as carbon-13.It comes from plants such as corn. The researcher found the telltale(报警的） form of carbon in an earlier study. They found bears in some places ate a large share of people's leftovers(剩饭）．Sometimes,these leftovers could make up more than 30 percent of a bear's diets,Pauli note.
In the new study,Kirby looked at the effect of diet on hibernation. Bears usually sleep for four to six months,during which female bears give birth. Kirby and her colleagues focused on 30 female bears around Durango, Colo. These bears were watched over by the state's parks and wildlife department. The team first tested bears for carbon-13.They found the ones that ate more human-related food tended to hibernate for shorter periods.
Studies on smaller animals show that hibernation may slow the aging process. If true, shortening the seasonal sleep may have an ill effect on bears. To test it, the researchers tested for relative changes in the length of telomeres(染色体端粒）。In the new study,bears that hibernated for shorter periods tended to have telomeres that shortened more quickly than those of other bears. This suggests the animals were aging faster,the team says.
The bears didn't always meet Kirby's needs for several kinds of data, so she can't say there is a direct and "certain" connection between what bears eat and aging. So far,Kirby calls the evidence "suggestive".
【小题1】What does the new study show about bears?| A．They have much difficulty in getting food. |
| B．Hibernating is their best way to stay young. |
| C．Eating human food might cause fast aging. |
| D．They hibernate for shorter periods than before. |
| A．Hunters usually use human food as bear bait. |
| B．Carbon-13 levels will fall if bears eat human food. |
| C．Bears seem to be able to find human food on their own. |
| D．Many bears only eat people's leftovers as their diets. |
| A．Hibernating for enough time. |
| B．Being weak with hunger. |
| C．Eating much human food. |
| D．Slowing the aging process. |
