Avoiding predators is important to migrating birds but to do that they must be able to recognize those predators, said biologist Joseph Nocera, who conducted the research with Queens University Professor Laurene Ratcliffe.

The scientists tested whether migratory songbirds observe the anti-predator behavior of local birds, which are familiar with local predators. One such behavior is "mobbing," during which birds approach potential predators emitting loud, broad-frequency calls that act as threat signals.

The scientists posited migrating birds might gain information about predator identification by listening to mob calls of other species.

To test their theory, they broadcast alarm calls of black-capped chickadee, common in North America, and blue-gray tanagers, common in Central America, to birds migrating between Canada and Belize.

Belizean resident birds responded only to the tanager calls but migrant birds responded to both the tanagers and the chickadees.

That, Ratcliffe said, is the first evidence that migrating birds pay attention to the anti-predator behavior of local birds during migration.

The study that included Philip Taylor of Acadia University appears on-line in the journal Behavioral Ecology and Sociobiology.