The woodlots were less than 20 acres and had row crops surrounding them on at least three sides. Dunning and Packett made observations in both spring and autumn.

There were 76 different species of migratory birds found in the woodlots, with no statistical differences in the number of species or overall population of birds based on distance from streams.

Packett said the birds, which travel thousands of miles between South and Central America and Canada twice a year, sometimes just need a place to stop along their journey.

As forests have been cleared for development, agriculture and other uses, those birds have to make do with whatever patches of forest they can find when they become tired or encounter bad weather.

'They don't make the trip all in one jump. It can be thousands of miles they have to fly,' Packett said. 'They need safe places to stop, eat and rest. If they don't have that, they might not survive,' he said.

These findings were published in the current issue of The Auk, the journal of the American Ornithologists' Union.