Dental polymorphism of the raccoon dog in indigenous and invasive populations: internal and external causation

Abstract

In total, 721 specimens from eight populations of the raccoon dog Nyctereutes procyonoides across native and colonized areas have been studied. The most polymorphic populations inhabit the European part of Russia and a part of the native area. The raccoon dog from Eastern Poland and the Primorie Far East is characterized by low intrapopulational variability. Quantitative genetic variations in the studied populations indicate a relatively higher level in the population from the Primorie Far East compared to the Southern Vologda and Eastern Poland. The pattern of morphological variability in the raccoon dog is shaped by such factors as the latest phylogenetic history of the species and the structure of the morphotype frequency in the time of the divergence of the populations on both micro-and macro-geographic levels. The influence of geographic and climatic factors forms a well-pronounced trend towards diversification in tooth morphology, which is most probably the consequence of adaptations to changes in the food niche.