Niche overlap and sett-site resource partitioning for two sympatric species of badger

Competition for resources can be a determining factor in whether similar species can co-exist. As an example of such intra-guild competition, we investigated sett (den)-site selection by two sympatric species of badger, the Chinese ferret badger (Melogale moschata) and die hog badger (Arctonyx collaris) in Houhe National Nature Reserve, central China. As members of the same guild we predicted that competition should occur between these species; and that their relationship along various niche dimensions should be affected by their five-fold difference in body size. We tested mechanisms facilitating coexistence in terms of sett sites at two spatio-temporal scales: (1) habitat selection; (2) internal den-microhabitat conditions. Logistic regression models revealed that ferret badgers selected sites characterized by dense, species-diverse shrub cover, low elevation and low tree cover. Discriminant function analysis revealed that these primary differences were attributable to slope angle, shrub cover and human activity. Niche overlap value, in terms of sett-site characteristics, was 0.359 (values in excess of 0.6 often limit viable coexistence). At the microclimatic scale, both the absolute, and range, of temperature values within setts also differed significantly between M. moschata and A. collaris. Our findings for these little-known, co-existing badger, species provide evidence for two mechanisms (trade-off in relative abilities to exploit different habitats and microhabitat) facilitating niche separation, with regard to den site selection.