Causes and Rates of Mortality of Swift Foxes in Western Kansas
Marsha A. Sovada, Christiane C. Roy, J. B. Bright, and James R. Gillis
Abstract: Knowledge of mortality factors is important for developing
strategies to conserve the swift fox (Vulpes velox), a species being
considered for listing under the Endangered Species Act, but available information
about swift fox mortality is inadequate. We used radiotelemetry techniques
to examine the magnitude and causes of mortality of swift fox populations
in 2 study areas in western Kansas. One study area was predominantly cropland,
the other rangeland. Mortality rates, calculated using Kaplan-Meier estimation
techniques in a staggered entry design, were 0.55 ± 0.08 (
± SE) for adult and 0.67 ± 0.08 for juvenile swift foxes. We
did not detect differences between study areas in mortality rates for adults
or juveniles. Predation by coyotes (Canis latrans) was the major cause
of mortality for adult and juvenile swift foxes in both study areas, and vehicle
collision was an important mortality factor for juveniles in the cropland
study area. No mortality was attributed to starvation or disease.
Key Words: Canis latrans, coyote predation, interspecific competition, Kansas, mortality factors, mortality rates, swift fox, Vulpes velox.
Sovada, Marsha A., Christiane C. Roy, J. B. Bright, and James R. Gillis. 1998. Causes and rates of mortality of swift foxes in western Kansas. Journal of Wildlife Management 62(4):1300-1306.
This resource should be cited as:Sovada, Marsha A., Christiane C. Roy, J. B. Bright, and James R. Gillis. 1998. Causes and rates of mortality of swift foxes in western Kansas. Journal of Wildlife Management 62(4):1300-1306. Northern Prairie Wildlife Research Center Online. http://www.npwrc.usgs.gov/resource/mammals/foxmort/index.htm (Version 04DEC1997).
Table of Contents
- Introduction
- Study Area
- Methods
- Results
- Discussion
- Management Implications
- Acknowledgments
- Literature Cited
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