Every fall, thousands of chimney swifts migrate through Baltimore, swirling at night into an old smokestack in Hampden and other locations to sleep in sheltered spaces.
But the numbers of these miraculous but often disrespected birds -- sometimes called "flying stogies" because of their taste for ash-tray like accommodations -- are declining across the U.S. because many new homes have metal-lined chimneys that kill the birds. The swifts' homes in hollow trees and caves are also disappearing.
