Individual differences in den maintenance effort in a communally dwelling mammal: the Eurasian badger

Abstract

Group living has potential costs in terms of relative fitness for individuals that invest effort in activities providing general benefit, if other competing individuals exploit those activities and accrue similar benefits at no cost. We examined the roles of individual badgers,Meles meles, in the den maintenance activities of digging and bedding collection at their communal setts. Twenty per cent of adults and yearlings were responsible for 60–90% of the observed digging and bedding collection effort. Overall males tended to dig more than females, while durations of bedding collection were similar. Among adult and yearling males and females, individuals with a high percentage of days observed at the sett (high site fidelity) performed more digging and collected more bedding than transients and badgers of low site fidelity. Males of high status (large, mature, frequently copulating individuals) were more likely to dig than males of low status. Principal component analysis indicated negligibly low correlation between status and site fidelity for males. We hypothesize that while highly resident adult females benefit from extending the sett to avoid direct reproductive competition, males of high status and site fidelity might extend the sett to encourage receptive breeding females in their home group to stay and/or to improve survivorship of sired litters. Other categories of individual depend on the sett for shelter but, perhaps having less to gain from extending it, adopt a less active role in sett maintenance.