Genetic relatedness and female spatial organization in a solitary carnivore, the raccoon, Procyon lotor

Among mammals, some of the most common types of cohesive social groupings originate from natal philopatry through the extended mother family. This retention of females within social groups (i.e. the nonrandom dispersion of female relatives in space) should affect population genetic structure. We examined the relationship between genetic relatedness and female spatial organization in a wild population of the North-American raccoon, Procyon lotor, a solitary carnivore in east Tennessee. Multilocus genetic band-sharing data and 3 1/2 years of radiotelemetry observations were used to study the spatial and genetic relationships among 38 adult females. DNA amplification employing primers of arbitrary sequence (random amplified polymorphic DNA; RAPD) indicated that female philopatry in raccoons led to a greater likelihood of neighbours being more related than expected by chance. Genetic distance based on RAPD band frequency was positively correlated with spatial distance among females (P = 0.0001) and genetic similarity was positively correlated with the extent of home-range overlap (P = 0.0028). Philopatry seemed biased towards females; average female-female similarities were greater than average male-male similarities (P = 0.0001), or average male-female similarities (P = 0.0001). High home-range overlap among some females with low or moderate levels of band sharing indicated that maternal inheritance of space was not a prerequisite for establishing or sharing home ranges. Female philopatry was the most probable explanation for the nonrandom spatial and genetic association of raccoons in east Tennessee.