Genetic diversity and population structure of the grey wolf (Canis lupus Linnaeus, 1758) and evidence of wolf × dog hybridisation in the centre of European Russia

Abstract

Throughout history the human–wolf interaction has not evolved in favour of the wolf, however, wolves have never been endangered in Russia. The wolf (Canis lupus lupus L., 1758) population in the central part of European Russia is relatively high, where environmental conditions, such as relatively undisturbed habitats, wide forested areas and abundance of natural prey, have always contributed to the long-term survival of the species. The human persecution of wolves has resulted in almost total extinction of the species in many European countries. In Russia, extermination campaigns have led to severe fluctuations in the number of wolves during the second half of the twentieth century, however, since the early 1990s there has been a tendency towards constant growth in the numbers. Previous studies provided preliminary data on population genetics of the wolf population in European Russia and have generally shown homogeneity of the population structure as well as detecting genetic bottleneck. However, the comprehensive study of genetic diversity and population structure during the period following the last severe decline is of great interest. Another important aspect in the study of wolf populations is the assessment of the magnitude of wolf × dog hybridisation, which is a phenomenon of conservation and social significance. We used 101 samples from the wolf population and 32 dogs to examine population structure, genetic diversity and events of interspecific hybridisation in the centre of European Russia, based on analysis of 11 autosomal microsatellites. In the studied region, wolves exhibit a high level of genetic diversity (H_E = 0.79 ± 0.03, H_O = 0.74 ± 0.01, N_A = 10.00 ± 5.02) which is superior to that in most European populations. Analysis of temporal samples suggests a slight increase in heterozygosity over time, although in the first period following population decline, the level of genetic diversity is not depleted. We found a lack of spatial structure and a weak pattern of isolation by distance (b =  − 0.007, P < 0.001), which are clear cases of intense gene flow and social organisation of the species. Our preliminary results suggest a relatively low rate of hybridisation in the studied region (around 3%), however, additional studies are needed to provide more reliable conclusions on this topic. This paper is the first attempt at both a detailed study of spatio-temporal population genetics and analysis of hybridisation in the wolves of Central Russia.