97 學年度學測英文 第 43 題

Howler monkeys are named for the long loud cries, or howls, that they make every day. They are the loudest land animal and their howls can be heard three miles away through dense forests. Male howler monkeys use their loud voices to fight for food, mates, or territory. Everyone starts and ends the day by howling to check out where their nearest competitors are.

Interestingly, when there are few howler monkeys in an area, the howling routine takes on a different pattern. In Belize, where howler monkeys were newly reintroduced into a wildlife sanctuary, the howler monkeys were heard only a few times a week rather than every day. Apparently, with plenty of space and no other howler monkeys around, there was no need to check on the whereabouts of their competitors. At the sanctuary, keepers now use recorded howler sounds from a distance so that the monkeys feel the need to make the territorial calls as they would do in the wild. In the future when the population grows, there will be no need for the recording because the howler monkeys will have more reason to check in with the neighbors to define their own territories.