Maternal Investment And Habitat Selection By Dall's Sheep

Abstract

Maternal behaviors and selection of habitat during lambing by Dall's sheep (Ovis dalli) were studied in Denali National Park and Preserve, Alaska, from April through July in 1988 and 1989. Climatic conditions in early spring differed between years; plant phenology was delayed by two weeks in 1989. Births were later and less synchronous in 1989. Females appeared to respond to variation in timing of births by modifying patterns of maternal investment; ewes nursed lambs for greater total time following parturition, but reduced total time spent nursing more rapidly in 1989. Selection of habitat characteristics varied with lambing chronology; terrain features related to avoidance of predators and sites with milder climatic conditions were selected during peak lambing. Variation between years in group sizes strongly influenced habitat selection. When corrected for variation in group size, no significant differences between years in selection of habitat were identified. <p>