I mentioned this a few weeks back.
Hazards of Migration
I've been asked by several friends to explain the large number of dead birds being found.
Death during migration takes a heavy toll. It is estimated that half of all migrants heading south for the winter will not return to breed in the spring.
Predation and bad weather are two natural causes of mortality during migration.
Birds migrating are in a weak and venerable state, assisting with feeders and bird baths help tremendously and in more ways than the obvious.
Collisions with buildings, windows, and other structures is a human-made danger. Unfortunately, many birds cannot distinguish the difference between real sky and a reflection of the sky in a window.
During migration millions birds fly full tilt into windows and are fatally injured or injured and fail to complete their migration.
Planting trees and installing window awnings to block the sun from hitting the window may eliminate some reflection but Putting a bird feeder on or within a few feet of a window helps to slow birds down and lessen the effect of impact.
Bird baths help in much the same way by having the bird stop and hopefully become aware of windows and other obstacles it might not otherwise recognize.The feeders and water in Bird Baths also act as a refueling station and assist the bird in completing the journey.http://ambergriscaye.com/forum/ubbthreads.php/topics/418140/Re_Death_by_Migration.html#Post418140