MIGRATION OF RED-TAILED HAWKS {BUTEO JAMAICENS1S) FROM NORTHWEST WYOMING

摘要

While a common species throughout most of the United States, little is known on the migration habits of Red-tailed Hawks {Buteo jamaicensis). From 1999-2002, we tracked 16 adult Red-tailed Hawks from their breeding grounds in northwest Wyoming using Argos PTT transmitters. Our objectives were to identify dates and duration of migratory movements, stopover sites, and identify migration routes and wintering areas. We found the mean migration initiation date from the breeding area was 13 October, mean fall migration duration including stopovers was 23.3 days, mean distance of fall migration was 2489.6 km, and mean end date of fall migration was 5 November. Wintering locations were in Mexico and ranged from the southern Mexican state of Chiapas north to Sonora and Chihuahua. The mean number of days spent on the wintering grounds by tracked hawks was 133.1. The mean departure date from wintering grounds to breeding areas was 17 March, mean spring migration duration including stopovers was 22.1 days, mean end date of spring migration was 8 April, and mean distance of spring migration was 2 490.3 km. Most birds made stopovers during both fall and spring migration which varied in location and duration. Using satellite telemetry, we identified wintering locations of Red-tailed Hawks breeding in northwest Wyoming and confirmed a leapfrog migration pattern with no concentrated migration routes from the breeding area to non-breeding areas. Received 6 February 2015. Accepted 23 July 2015.