Estimating Survival Rates of Snowshoe Hares

Survival rates were estimated by 4 methods (minimum survival, Jolly-Seber, and 2 radio-telemetry techniques) for snowshoe hares (Lepus americanus) near Kluane Lake in the southern Yukon from 1978 to 1982. Jolly-Seber and minimum survival estimates from live trapping underestimated survival rates by 13 and 30%, respectively, when compared to telemetry estimates, which produced higher and nearly identical estimates of survival. Telemetry methods are recommended for estimating survival of hares. J. WILDL. MANAGE. 50(4):592-594 Survival is an important demographic parameter, and changes in juvenile and adult survival rates are known to drive the 10-year snowshoe hare cycle (Keith and Windberg 1978). Two detailed analyses of this cycle (Keith and Windberg 1978, Krebs et al. 1986) found that survival rates tended to be underestimated (assuming census data and reproductive rates were accurate). In this paper we compare 4 methods of estimating survival rates for snowshoe hares to determine the source of this bias. We thank B. S. Gilbert, R. A. Moses, and C. J. Krebs for their help in collecting these data and the Arct. Inst. North Am. for providing facilities at Kluane Lake. This research was supported by the Nat. Sci. and Eng. Res. Counc. Can.