Sett use in European badgers Meles meles

The European badger Meles meles constructs burrows of two basic types: 'main setts' and 'outliers'. We examined daytime burrow use year-round in 19 radio-collared badgers belonging to six different social groups, in order to test the hypotheses relating use of multiple sleeping sites to ectoparasite avoidance and social status. Ten animals rarely or never slept away from the main sett, while the remaining nine animals spent 20-73% of their days in outliers, mainly in summer. Outlier use was not related to sex or body condition, but animals that used outliers tended to be younger and had larger numbers of fleas than those that remained in the main sett year-round. Within the main sett, all the members of a social group had overlapping ranges: i.e. the sett was not divided into separate 'territories'. Group ranges were smallest in winter and largest in summer/autumn. Nest chambers were usually shared between at least two members of a social group on any one day, but males slept alone more often than did females. Individuals tended to cluster together in the same nest chamber more in winter than at other times of pear, presumably to gain thermoregulatory advantage from huddling. We conclude that the pattern of burrow use in badgers is complex. Use of space within the main sett and tendency to disperse to outliers in the summer are in pan affected by ectoparasite infestation, while use of space within the main sett is also influenced by variables such as sex and age that may reflect social status.