Migration and ranging of Peregrine Falcons wintering on the Gulf Of mexico coast, Tamaulipas, Mexico

Movements of 11 female and 1 male adult Peregrine Falcons (Falco peregrinus) wintering in coastal Gulf of Mexico, Tamaulipas, Mexico, were monitored with satellite-received transmitters (PTTs), 1997-1998. Median areas for minimum convex polygon winter home ranges at 50% and 90% levels (both years) were 1173 and 8311 ha, respectively. Most birds left wintering grounds in the first week of May. Duration of northward migration averaged 30 days. Distances between capture location and summer settling place were between 4580 and 5844 km; birds traversed 40.4-46.4 degrees of latitude. Birds summered between far western Canada and coastal west Greenland. One was followed to the same summering ground in both years. Autumnal migration routes were through the middle of the continent, and initiated in August and September. Falcons arrived on wintering grounds in September and October, averaging 40 days to make the journey. PTT data and capture locations of birds trapped in more than 1 year suggest fidelity to wintering areas, although perhaps not particular winter home ranges.