Habitat Selection by Neonatal Black-Tailed Deer: Climate, Forage, or Risk of Predation?

Abstract

We studied habitat selection by neonatal (2–10 days old) black-tailed deer ( Odocoileus hemionus columbianus ) on Big Flat, Trinity Co., California, during June–August, 1992–1994. Even deer 2–3 days old frequently followed their mothers and occurred in social groups with other adult deer. Neonates used south-facing slopes with gentle terrain and high variability in overstory and concealment cover more often than expected from availability of those habitat variables. Young deer also selected sites with more herbaceous vegetation but avoided areas with more browse. Forage was more digestible at sites with neonates than at random sites, but no difference occurred in nitrogen content of forage between those sites. Variables identified as important components of habitat for young deer more likely were related to the thermal environment of the neonate and nutritional demands of lactating females than to risk of predation. Alternatively, variation in concealment cover may have been related to predation risk, resulting in a positive relationship between forage availability and risk predation. Minimizing the predation: forage ratio was not a viable model for explaining habitat selection in neonates.