Friday, September 12, 2008
Two-Observer Method Limits Inaccuracies of Forest Animal Surveys
Dense vegetation, rough terrain, and other variables may make it difficult to monitor forest-dwelling mammals. When direct counting is not practical, researchers in forested regions often rely on surveys of scat (animal waste) to study the abundance and distribution of the large animals. Biases, such as using different observers, may limit the usefulness of using scat as a substitute for direct counting. USGS wildlife biologist Kurt Jenkins and co-author recently published results of a study to adjust for detection biases during surveys of Roosevelt elk and Columbian black-tailed deer in Olympic National Park, Washington. Two observers sampling the same area provided a cost-effective way of reducing bias. It is important for future researchers to account for sampling inaccuracies, and the double-observer methods are readily adaptable to study large animals when direct counting is difficult.
Jenkins, K.J., Manly, B., 2008, A double-observer method for reducing bias in faecal pellet surveys of forest ungulates: Journal of Applied Ecology, v. 45, p. 1339-1348. [Abs] [FullText] Catalog No: 1717
Contact:
Kurt
Jenkins,
FRESC,
360-565-3041,
kurt_jenkins@usgs.gov
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