SEASONAL AND ANNUAL SURVIVAL OF EMPEROR GEESE

Population levels of emperor geese (Chen canagica) in Alaska in 1993 w ere about half that estimated in the 1960s. Survival information is ne cessary for managers to decide how to best enhance recovery of this sp ecies to former levels. We calculated seasonal and annual estimates of emperor goose survival from resightings of neck-collared birds. Geese were neck collared in 1988-90 on their breeding grounds in the Yukon- Kuskokwim Delta, Alaska, and resighted each spring and fall, 1988-92, at staging areas on the Alaska Peninsula. Adult monthly survival rates during overwinter periods (1 Oct-30 Apr) were not different (P = 0.28 1) among years (S' = 0.940, SE = 0.009), whereas monthly rates of over summer (1 May-30 Sep) survival showed annual variation (P = 0.048). Ho wever, we constrained oversummer survival to a single estimate of 0.98 0 (0.010). Monthly survival estimates for juveniles during their first overwinter period did not vary among years (P = 0.999) and was 0.710 (0.018). Subsequent monthly survival for juveniles was 0.943 (0.010), similar to that for adults. We developed an adjustment procedure to ac count for philopatric behavior of geese and this enabled us to use dat a for postbanding (1 Aug-30 Sep) periods. Survival estimates were low compared with those for other goose species, particularly for juvenile s. We addressed collar loss and heterogeneity in resighting probabilit ies and felt their contribution to potential model bias was insignific ant. Annual survival among adults (S' = 0.631, SE = 0.023) was not dif ferent (P = 0.709) from that observed during 1982-85 (Petersen 1992). The similarity in survival rates in these studies suggests that harves t regimes did not differ between the 2 periods. This suggests that con tinued subsistence harvest has contributed to persistent low populatio n levels in emperor geese.