Genetic relatedness affects socio-spatial organization in a solitary carnivore, the European pine marten

Abstract

Genetic relatedness among individuals can play a major role in the socio-spatial organization of mammals. However, only a few studies have documented kin-related spatial pattern in solitary medium-sized carnivores. Using radiotelemetry and genetic data from 15 individuals (seven males and eight females), we investigated the relationship between kinship and spatial organization (distance and overlap between home ranges) in the European pine marten Martes martes in a wooded area of central Italy. Data analysis included 45 pairs (10 individuals) tracked in spring and summer and 66 pairs (12 individuals) tracked in autumn and winter. Kinship, distance between home ranges and proportion of home range overlap were also compared among inter- and intra-sexual pairs. Spatial distribution of pine martens was affected by genetic relatedness, so that individuals living in close proximity or occupying the same area were also more likely to be closely related. Female pairs had a higher proportion of overlap of their home and core ranges than male pairs. Male pairs were also less related than female and inter-sexual pairs, showing a pattern of space use consistent with male-biased dispersal and female philopatry. Most of the females that overlapped their home and core ranges were genetically related, while only a third of the few male pairs occupying the same territories were kin. However, our results seem to indicate that positive association between home range overlap and relatedness was mainly a consequence of common female philopatry rather than kin-biased tolerance. Male-female dyads had the highest percentage of related individuals overlapping their home and core ranges, suggesting that spatial segregation is unlikely to play a role in preventing encounters between kin.