Sexual Segregation and Competition in Roosevelt Elk

Abstract

I documented segregation of the sexes in a high density population of Roosevelt elk (Cersus elaphus roosevelti) and examined if segregation could be attributed to competition. The population was segregated because the proportion of adult males in groups of females was less than the proportion of adult males in the population. The extent of spatial overlap ranged from 19% in April to May to 53% in August to September. Females were distributed in and near meadows and males occupied meadows and forested habitats. A meadow where >50% of all males and females were observed was partitioned by the sexes. Grazing density (animals per day per ha) was higher in the part of the meadow frequented by females. Scramble competition is at least part of the explanation for sexual segregation in this population.