Dispersal of subadult moose (Alces alces) in a nonmigratory population

Abstract

Dispersal of subadult moose (Alces alces) in a sedentary population in central Sweden was studied during 1983 – 1989 by radio-tracking individuals for up to 11 seasons after their abandonment by the cow. Linear distance between geometric centers of natal area and consecutive home ranges increased with time among males, but not by more than about 4 km. The main increase occurred in autumn, probably due to rutting activities. Females maintained a fairly consistent distance of approximately 1 km throughout the study period. Seasonal home range overlap of natal area was negatively correlated with time for both sexes, but the patterns in the decrease differed. For males, the overlap was 10–40% after the first year, whereas female home ranges never overlapped by less than 40%. Overlap of consecutive seasonal home ranges increased significantly with age in both sexes. Neither sex dispersed out of the study area, since the animals were highly philopatric. The absence of dispersal (high philopatry) in moose in Fennoscandia is an important factor affecting demographic processes (and perhaps also genetic processes) within and between populations. It is important to distinguish different subpopulations of moose and manage them with respect to their unique demographic features.