This is bird note.

resident Cooper's Hawks that nest in the urban areas of Albuquerque, New Mexico are thriving.

So much so that they could be out-competing other migratory Cooper'sks that nest in the surrounding countryside.

Just what advantage do these city hawks have?

Cooper's hawks are crow-sized raptors that nest in tall trees and prey mostly on birds.

Since the 1980s, populations of white-winged doves, perfect hawk prey, have exploded in urban Albuquerque.

This easy prey gives the urban birds a competitive advantage over hawks in more natural habitats where prey is less concentrated.

How's that? Well, rural hawks migrate south in winter to hunt, while urban hawks remain year-round,

according to a study by Brian Millsap of New Mexico State University.

As the resident city-hawk population has grown, the birds have started emigrating to the countryside,

claiming rural nesting sites before the migrating hawks return.

But that's not necessarily bad news for the species as a whole.

The soaring numbers of urban Coopers-Hocks could help preserve the genetic diversity of the species far into the future.

For Bird Note, I'm Mary McCann.