Female-biased sexual size dimorphism (SSD), a condition common in North American chipmunks, occurs when females are larger than males in a species. We examined the influence of body size on dominance of captive female Townsend's chipmunks (Tamias townsendii Bachman, 1839), a species that exhibits female-biased SSD, in all-female and mixed-sex dyadic encounters. In all-female dyads, large female chipmunks were more frequently dominant over small female opponents. In mixed-sex dyads, large females were always dominant over small males. Female-biased SSD in Townsend's chipmunks appears to indirectly allow large females to more frequently dominate small female and male conspecifics. Greater dominance could increase reproductive success of large female chipmunks by increasing access to resources.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology