Great Basin Naturalist


We studied seasonal cattle grazing as an agent of ephemeral habitat fragmentation on a newly reintroduced population of California bighorn sheep (Ovis canadensis californiana) in Big Cottonwood Canyon, Idaho, 1988–89. We evaluated the hypothesis that bighorn sheep avoid cattle. We documented sheep response to the proximity to cattle by direct observation. The core areas used by bighorn and distances to escape terrain generally decreased as cattle moved closer to sheep. Likewise, sheep moved from cattle as cattle approached them. Severity of response we observed is in marked contrast with that reported for established bighorn populations, suggesting that newly reintroduced bighorn sheep are more highly sensitive to the presence of cattle.