Why Band Young Peregrine Falcons
Banding young peregrines provides important information on the birds' movements and is essential to understanding their habitat needs year-round. The nestlings are removed from the nest box or natural nest site for a short time and metal bands are placed on the birds legs. These bands are uniquely lettered and numbered so that if the falcons are observed later, or found injured or dead, they can be identified. When the birds are banded they are also checked for overall health and condition. Also, any unhatched eggs, egg shell fragments and prey remains are collected for examination. The unhatched eggs are checked for embryo development and analyzed for contaminants. The prey remains provide additional insight into peregrine falcon feeding habits.
Because of the size difference of adult male and female falcons (females being larger) two different sizes of leg bands are needed. Banding is done when the nestlings are about three weeks old because they do not run out of the nest box or attempt to fly at this stage. In addition, at three weeks of age the young birds can be sexed by measuring the width of the legs.
Adult peregrine falcons, particularly the females, are quite aggressive during the banding operation. Individual birds vary in their level of aggressiveness, but many will fly very close to the bander and may even strike them with their feet! Biologists try to complete the banding process as quickly as possible to reduce stress on the birds.