A new study by students with the Montana State University Museum of the Rockies in Bozeman, Montana has shown that the morphology of the talons of birds of prey are related to how they are used during prey capture and feeding.
According to some reports, this is the first time a study on the functional morphology raptor talons has been conducted.
The study has shown that the enlarged talons of on the first digit of members of the family Accipitridae are utilized for restraining large prey items, whereas members of the family Pandionidae have recurved talons of uniform size on each toe which aids in capturing fish like fish hooks.
The study has also shown that many owls, which feed on smaller prey items, utilize the strength in their feet to constrict prey items more than they use their talons. Additionally, falcons typically dispatch prey by striking them and then killing the prey items by breaking the neck with a tomial tooth on the beak.
You can read more at:
Denver W. Fowler, Elizabeth A. Freedman, John B. Scannella. Predatory Functional Morphology in Raptors: Interdigital Variation in Talon Size Is Related to Prey Restraint and Immobilisation Technique. PLoS ONE, 2009; 4 (11): e7999