Stone’s sheep (Ovis dalli stonei) lambing and nursery habitat selection

Abstract

Wildlife conservation often focuses on mitigating disturbance in critical habitats, like reproductive ranges. We studied lambing and nursery habitat selection by Stone’s sheep (Ovis dalli stonei (J.A. Allen, 1897)) in the Cassiar Mountains in British Columbia. We estimated the timing of parturition and delineated lambing and nursery habitats based on movement behaviours of collared females (n = 18) and vaginal implant transmitters. We identified 23 lambing events in 2018 (n = 4), 2019 (n = 13) and 2020 (n = 6). The median birth date was 17 May and ranged from 3-May to 14-Jun. Females remained in lambing habitats from 1.5 to 11.3 days with a median of 5.5 days. We examined habitat selection during the lambing and nursery periods at the home range scale using resource selection functions, and at a finer scale using integrated step selection analyses. Females selected southwest slopes in rugged terrain at mid elevations, suggesting selection for warmer micro-climates and features that facilitate predator avoidance. Females avoided habitats near roads during the lambing period but showed selection for habitats near roads during the nursing period. We developed predictive maps of suitable lambing and nursery ranges to inform land planning to help reduce overlap of anthropogenic disturbance with potential reproductive habitats.