Cattle or Sheep Reduce Fawning Habitat Available to Columbian Whitetailed Deer in Western Oregon

Abstract

Abstract We studied responses of Columbian white-tailed deer (Odocoileus virginianus leucurus) to cattle and sheep in western Oregon because of viability concerns. We used radio-telemetry, observations from horseback, and searches with a trained dog to determine fawning habitat, dam home ranges, and habitat use by fawns. Dams (n = 12) shifted ( = 366 m, P < 0.05) their center of activity by establishing disjunct areas of use prior to fawning. Ten dams exhibited their largest Euclidian movement during May—July; 7 females undertook extended ( = 1445 m) forays during spring. Three natal sites averaged 1926 m from the center of the dam's annual home-range. Dams avoided (P < 0.05) areas with livestock during fawning; 3 fawns were encountered during 243 h of searching (1 fawn/91.4 h) in areas with livestock stocking levels of ≥2.5 animal use month/ha (AUM), whereas 39 fawns were encountered during 275 h of searching (1 fawn/7.1 h) in areas with <2.5 AUM of livestock use. Natal areas (n = 52) were in denser luxu...