Winter Ranges of Migratory Turkey Vultures in Venezuela

Authors

Erik M. Hedlin, University of Saskatchewan
C. Stuart Houston
Philip D. McLoughlin, University of Saskatchewan
Marc J. Bechard, Boise State UniversityFollow
David R. Barber, Hawk Mountain Sanctuary
Keith L. Bildstein, Hawk Mountain Sanctuary

Document Type

Article

Publication Date

6-2013

DOI

http://dx.doi.org/10.3356/JRR-12-37.1

Abstract

We used four Global Positioning System (GPS) satellite transmitters to calculate the wintering ranges of migratory Turkey Vultures (Cathartes aura) that breed in Saskatchewan, Canada, and winter in Venezuela. Between 2007 and 2011, 95% fixed-kernel estimators of range size varied from 54 to 76 731 km² with an average of 16 814 ± 28 606 km² (SD), while those calculated with 95% Minimum Convex Polygons ranged from 22 to 46 778 km² and averaged 9545 ± 17 356 km². The smallest wintering range was comparable to previously reported range sizes, but our largest wintering range greatly exceeded anything yet recorded. Variation in winter range sizes may be attributed to resource availability, migration costs, and the absence of obligations associated with breeding. Each vulture had a “primary nocturnal roost” to which it returned frequently; each spent more hours (evenings, nights, and mornings) at and within 1 km of such roosts, than it did foraging during midday. Our results increased our understanding of the feeding and movement ecology of North American migratory Turkey Vultures overwintering in South America.

Publication Information

Hedlin, Erik M.; Houston, C. Stuart; McLoughlin, Philip D.; Bechard, Marc J.; Barber, David R.; and Bildstein, Keith L.. (2013). "Winter Ranges of Migratory Turkey Vultures in Venezuela". Journal of Raptor Research, 47(2), 145-152.