Life-History Effects of Chemical Immobilization and Radiocollars on Mountain Goats

Abstract

To assess the potential effect of our research activities on mountain goats (Oreamnos americanus), we tested for long-term behavioral, reproductive, and survival effects of immobilizing and radiocollanng goats in an unhunted population in Alberta, Canada. Chemical immobilization of females with xylazine hydrochloride 1-5 months before rut decreased kid production the following year for 3 and 4 year olds (P = 0.02), but not for older females (P = 0.67). Following capture, drugged females abandoned their kids more often than undrugged females (16 vs. 2%; P = 0.02), and abandonment decreased kid survival (P 0.10). Chemical immobilization did not affect survival, foraging efficiency, or time spent alert for either sex (P > 0.20). Radiocollars had no effect on kid production or female dominance status and did not affect survival, foraging efficiency, or time spent alert for either sex (P > 0.10). Overwinter survival of captured and uncaptured kids did not differ. Kids with radiocollars appeared to have lower survival than uncollared kids, but the effect was not significant (P = 0.16). Our results suggest that handling affected reproduction and survival of mountain goats and underline the need to test for similar effects in wildlife field studies. We provide guidelines to reduce unwanted life-history effects on captured mountain goats.