Influence of the Environment on the Structure of the European Badger (Meles meles) (Mustelidae, Mammalia) Family Groups on the Oka–Don Plain

Abstract—Diverse variants of the social organization of European badger populations (Meles meles L.) are observed in different parts of the living range. This paper presents information concerning the impact of the environment on the structure of European badger family groups. Data of the authors’ own observations conducted at ten model sites in the years 2011–2018 were used as the study material. The model badger settlements studied are located on the Oka–Don Plain within the administrative borders of Saratov oblast. The results of route surveys, photo trap surveys, and correlation assessment revealed a direct and strong correlation of the area occupied by a family group and the size of the group’s forage territory to the number of individuals in the group (r = 0.875 and r = 0.715, respectively). Family groups of four types (group, polygynic, monogamous, and incomplete families) were distinguished. The group type of family is formed in areas most appropriate for the badger when the amount of available food is sufficient. Large family groups inhabit such sites and construct complex systems of burrows used by many generations of badgers. Polygynic families occupy territories similar to the first type, but characterized by a small size of the forage area. Since food availability is a limiting factor, these social systems do not develop into large family groups and consist of a polygynic family of an alpha male and several females with their offspring. A small area of the family territory and a large forage area are characteristic of the social groups of the third type. A small size of the territory available is also a limiting factor, which prevents the animals from forming social groups larger than a monogamous family. The fourth type of family groups called the incomplete family is formed under an insufficient size of the territory available combined with a small size of the forage area. Quantitatively, groups of this type include a single individual and, less often, a pair of animals. These types are not permanent structures, but rather replace each other under the influence of environmental factors. The development of a family group is limited by the total size of the area suitable for vital activity and by the amount of available food resources, which is a solution to the problem of resource allocation among animals of the species studied.