We trapped 994 hawks during spring migration in years between 1953 and 1972. We obtained sufficient numbers to comment on age or sex differences, or both, in the timing of migration of six species. Adults migrated earlier in most species, presumably because most adults but few juveniles breed. Adult male Sharp-shinned Hawks (Accipiter striatus) migrated significantly before adult females and the larger (presumably female) Red-tailed Hawks (Buteo jamaicensis) migrated significantly earlier than smaller individuals. Juvenile female Sharp-shinned Hawks and Cooper's Hawks (A. cooperii) migrated before males, probably because more juvenile females than males breed.