【英语时差8,16】搜寻coywolf（在线收听）

Once upon a time, wolves roamed the northeastern regions of the United States in plentiful packs.  But about a century ago, human development drove wolves away.  They retreated north, into Canada, and west into Michigan, Wisconsin and other Midwestern states.

Now, though, the wolf is making a comeback in upstate New York.  Sort of.  More accurately, wolves are returning in the form of coyote?wolf hybrids.

Scientists suspect that so?called coywolves first began appearing around the 1920s.  Coyotes migrating from western states began to interbreed with wolves in Canada.

Their offspring are larger than normal coyotes, which hunt rodents and small mammals.  Like wolves, coywolves hunt deer.  Also like wolves, coywolf males are larger than females.  And they hunt in packs and roam forests, similar to wolves.

But where wolves shy away from suburbs and other human settlements, the hybrids have inherited the fearlessness of pure coyotes.  In some areas in Canada, coywolf packs have been seen attacking sheep, cattle, and other domesticated animals in broad daylight.

Coywolves are, in effect, something like a new species.  Unlike mules and some other hybrids, they’re able to reproduce.  And they’re beginning to fill many of the ecological niches in the northeastern United States abandoned by wolves.