Post-Fledging Activity of the Red-Tailed Hawk
During a two-year study of post-fledging activity of Red-tailed Hawks (Buteo jarnaicensis) in the Gallatin Valley, Montana, in 1971 and 1972, data were collected on mortality, length of time the fledglings remain within the home territory, and characteristics of their movements out from, and possibly, back to their home territory. Mortality was found to be low during the first 18-25 days after fledging, when the young were quite inactive. Mortality also may be low until the young begin leaving the home territory. The length of time the young remained associated with the adults ranged from 30 to 70 days after fledging for all fledglings observed. For nest-mates, time spans between departures ranged from zero to 31 days after fledging. Movements of the fledglings out from and back to the home territory were variable. Some young made no movements out from the home territory until they left permanently, while others left and returned up to five times. The length of time the young remained associated with the adults, and thus within the home territory, did not determine the number of movements it made into the areas surrounding the home territory, before it left it permanently.