A bird in the bush is worth -- a lot

Highway travelers know the relief of finding a great place to stay after a long night on the road. Migrating birds are no different. A study led by a Princeton researcher has shown that birds expend more energy seeking food and shelter between the legs of their journey than they do flying.

"Flight itself is costly, but foraging and preparing for the flight is even more costly," said Martin Wikelski, a biologist and lead author of a study that involved tracking birds for hundreds of miles as they traversed the American Midwest.

One implication of the finding is that urban and suburban homeowners play a critical role in preserving migratory routes. The birds followed in the study often stopped in the backyards of populated areas to look for food and prepare for the next flight. "You really have to keep your garden in good shape so the birds can come through and make it up to Canada," Wikelski said. Migrating birds need bushes and some natural undergrowth, not just lawn and flower gardens, he said.

More details are available in a news release.