Social dominance and habitat utilization in Antechinus stuartii (Marsupialia)

Abstract

A trapping study of Antechinus stuartii was conducted in subtropical rain forest in 1971-72. Juveniles were communal during the period of abundant food and became solitary in autumn when food diminished. Dyad testing in a field observation cage permitted analysis of social dominance in males. Dominant males had individual ranges in habitats where resources permitted rapid growth throughout winter, whereas subordinate males, in poorer habitat, grew slowly. As winter mortality was low, the advantage of this superior food resource base may lie during the mating season, the more energetic dominant males being able to mate with more females. The probability of contribution to the gene pool by subordinate males appears low. Selection for high male reproductive effort is intensified by the brief annual mating season in this monoestrous species. The life history of this species appears to be geared to predictable seasonal food resources, but it may not be optimal throughout the present range, and the species appears to be evolutionarily trapped.