SURVIVAL OF RADIOCOLLARED ADULT MOOSE IN LOWER SUSITNA RIVER VALLEY, SOUTH-CENTRAL ALASKA

Estimates of survival for adult moose (Alces alces) are presented by s ex, season, and calendar year (CY) for 204 (66 M, 138 F) radiocollared adult moose monitored from aircraft in lower Susitna River Valley (LS RV) in southcentral Alaska during May 1980 through February 1991. Deat hs were attributed to capture problems, hunter kills, defense of human life or property (DHLP), illegal harvest, collisions with trains, and unverified other causes. Capture-related deaths were not included in survival analyses. Hunter kills were mainly censored from survival cal culations. Moose were censored from the study for loss of signal conta ct and shed radiocollars. Summer survival curves did not differ among CYs for females (P = 0.501) or for males (P = 0.819) or among sexes (C Ys pooled; P = 0.817). Autumn survival curves did not differ among CYs for females (P = 0.617) or for males (P = 0.617); a difference was de tected among sexes (CYs pooled; P < 0.001) with survival higher for fe males (0.98, SE = 0.007) than for males (0.90, SE = 0.032). We specula te that lower autumn survival in males was from bullet wounding, wound ing from rut-related fights with other bull moose, illegal harvest, an d fatal encounters with bears. Survival in winter and annual survival varied by sex and CY and was affected largely by mortality associated with accumulation of snow. Given low densities of wolves and no observ ations of wolf sign at mortality sites we contend that malnutrition wa s the main cause of mortality in deep snow winters. Nonhunting deaths of male moose in winter was not correlated negatively with hunter kill s of males in the precious autumn-early winter. Moose managers should be cognizant of nonhunting mortality of males in autumn and snow condi tions through mid-May to evaluate animal survival and to accurately pr edict size and composition of post-winter populations. Moose managemen t programs should be sufficiently responsive to modify autumn harvest quotas in accordance with survival data collected the previous winter 5 months after autumn post-hunt population surveys.