Lifetime reproductive success of territorial Male Yellow-Bellied Marmots

Abstract

Number of years as a territorial resident, number of adult females in the territory, mean age of the adult females, and mean matriline size were used to evaluate the lifetime reproductive success (LRS), measured as the number of young weaned, of adult male territorial yellow-bellied marmots residing on eight habitat patches (sites). Only mean age of females differed among sites. In univariate analyses, LRS was significantly related to the number of females present and the number of years resident. In multivariate analyses only the number of females present significantly affected LRS. When LRS was measured as the number of yearlings produced, mean matriline size and number of young were significant. Inbreeding, mainly father:daughter matings, did not affect the frequency of weaning or mean litter size, but survival of young was significantly lower. LRS of adult females was significantly related to the number of years a female was resident. Mean LRS was significantly greater in males than females and variance was much greater in males. Males that lived near a site before becoming territorial were significantly more likely to reproduce in their first year of residency than males who did not live near their site of territorial residence. LRS is greater in males that settle quickly with as many females as possible for as many years as possible.