Intra-population polymorphism of sympatric canids (Canis lupus, Vulpes vulpes, Nyctereutes procyonoides): craniometric data

Studying essential background of mammalian biology at the level of intra-population morphological diversity provides important information for understanding the patterns of formation and stability of complex biological systems, and serves as an important basis for developing in-situ management and conservation of biological diversity. The article discusses the factors and forms of manifestations of intra-population dimensional morphological diversity in three species of sympatric mammals of the Canids family in a limited geographical area within a 60-year time period. In the framework of statistical analysis of various forms of polymorphism for each of three forms, the magnitude of the dimensional and morphological variability, the features of this phenomenon and the possible mechanisms of influence of individual factors are discussed. It is shown that the dimension of sexual dimorphism (SSD) is manifested in the order of amplification in the row: the raccoon dog (ISD = 1.7), red fox (ISD = 3.01), wolf (ISD = 3.55). It is associated mainly with signs of jaw apparatus and carnassial teeth. In addition to sexual selection, SSD depends on the social organization of species. Spatial variability in the studied species is characterized by pronounced intra-population structure in the grey wolf and less pronounced in the red fox and raccoon dog. The driving forces of this form of polymorphism can be both the biological features of species with more or less characteristic territorial conservatism, and adaptation to local living conditions, which is manifested at the level of selectively significant functional odontological and maxillary features. Chronographic variability, present as an objective phenomenon, is characterized by different trends in each of the predators. It can be determined by adaptations to the food spectrum, and also has a random nature due to the high total death of animals. The ratio of the studied forms of polymorphism indicates the dominance of individual age and gender variability. The geographical (spatial) factor and chronographic variability should be considered as the second order of influence; they together determine the spatial-temporal dynamics of intra-population morphological diversity.