Habitat selection patterns of feral horses in southcentral Wyoming

Kelly K. Crane, Michael A. Smith, and Doug Reynolds

Authors are specialist, Rangeland Ecology and Watershed Management, Cooperative Extension Service; professor, Rangeland Ecology and Watershed Management Department; and Carbon County cooperative extension director; University of Wyoming, Laramie, Wyo. 82071.

Abstract

Feral horse habitat selection patterns and forage attributes on available habitats were studied on public rangelands of southcentral Wyoming. Environmental assessments preceding roundup of excess horses requires resource data to justify the number of horses removed. Randomly selected bands of horses were followed for 24-hour observation periods during the spring and summer to determine if they utilized habitats in proportion to their abundance. We also determined if forage abundance, succulence (an index to forage palatability), percent utilization, and dietary composition were related to habitats selected. Stream-sides, bog/meadows, and mountain sagebrush habitats were preferentially selected (p <0.05). Lowland sagebrush habitats were avoided and no apparent selection behavior was shown for grassland and coniferous forest habitats. Forage abundance, palatability, and percent utilization were higher (p < 0.05) in streamside and bog/meadow habitat classes. Diet composition indicated that sedges (Carex sp.), common in streamsides and bog/meadows, were an important forage of feral horses. Palatability and abundance of graminoid vegetation and proximity to preferred habitats seemed to be the primary influences on habitat selection by feral horses.

Key Words: forage abundance, succulence, utilization