Group size versus territory size in group-living badgers: a large-sample field test of the Resource Dispersion Hypothesis

Badgers (Meles meles) have been the focus for the development of a pervasiv e model of social grouping behaviour, relevant to a number of carnivore spe cies and other taxonomic groups - the Resource Dispersion Hypothesis (RDH). The RDH hypothesises that the dispersion and richness of resources in the environment provide a passive mechanism for the formation of groups,- even without any direct benefits of group living. However, few studies have test ed-the RDH in the field. The principal prediction is that, as opposed to en largement of territory sizes to accommodate more members, territory size (T S) is independent of group size (GS). Instead, TS is determined by the spat ial dispersion of resources, while GS is independently determined by the ri chness of those resources. However, these predictions provide only weak cor relative tests, especially in non-experimental field studies. The first pre dicts an absence of correlation and is therefore prone to Type II error, es pecially given the small sample sizes and errors in estimating TS and GS of mammals in the field. We tested for independence of territory size and gro up size in all years with available data since the beginning of the long-te rm badger study in Wytham Woods in 1974. We used two methods of TS estimati on, a sequential Bonferroni technique to adjust for multiple inference test s, a combined analysis and an analysis with pooled data. This prediction of the RDH could not be rejected on the basis of any of these analyses. Given this evidence that other processes are independently determining group siz e and territory size, further predictions of the RDH will be worth investig ating in considerable detail.