Mating system and genetic variance in a polygynous mustelid, the European polecat.

Abstract

The population genetic implications of mating system were investigated in European polecat Mustela putorius populations from western France, combining radiotracking survey and allozyme variation analysis. Mating period occurred from February to June and polecats showed a strategy of successive polygyny, a male consorting with 1.44 females during a brief period (2.9 days). Relatedness was largely sex biased, females (21%) being almost twice more related than males (13%) suggesting a natal philopatry. Nonetheless, breeding dispersal pattern appeared relatively complex. Males were the sex dispersing but the main strategy for male polecats consisted of short-term mating excursions in adjacent females ranges whereas long-distance dispersal only constituted an alternative breeding strategy. Despite their allozymic polymorphism level reaching 24% at p<0.05 for 38 scored loci, populations showed a high heterozygote deficiency as revealed by the F IS index averaging F IS = 0.383. Thus the mating system of such solitary mustelids may be poorly efficient to prevent inbreeding within populations.

Genetic neighbourhood and effective population size in the endangered European mink Mustela lutreola

“…Because most mink breed in their first year, it seems technically impractical to improve their generation time. The sexratio is consistent with a polygynous mating system such as found in the genetically related species, the European polecat (Lodé 2001). Furthermore, given the degree of variation in demographic parameters, there are reasons to suggest that the ratio N e =N may be overestimated.…”

Adult sex-ratio distortion in the native European polecat is related to the expansion of the invasive American mink

“…possible that some factors associated with reproductive costs (e.g. cub-raising, cub-defense, male harassment) are behind earlier polecat female mortality in the presence of American mink (Sidorovich, 2000a), because males do not participate in these tasks (Lodé, 2001). The sampling method did not affect the SSR, as the results of all methods (trapping/hunting, live trapping or road-kills) were malebiased.…”

“…For instance, the effective population size is below the total number of adults, being limited by the less abundant sex (Charlesworth, 2009), and thus current population censuses must be reinterpreted. Polecats show a polygynous system, with the male reproductive strategy consisting of short-term mating excursions in overlapping female home-ranges, including occasional long distance travel (Lodé, 2001). As every male consorts with 1-3 females, and females only mate with a single male (Lodé, 2001), subordinate males have little access to mating, with the polecat populations exhibiting a heterozygosity deficit and strong inbreeding (Lodé, 2001).…”

Mortality and reproductive patterns of wild European polecatsMustela putorius in Denmark

“…The male skew in the proportion of sampled polecats is unlikely to reflect the sex ratio of the live population as mustelid birth sex ratios do not appear to be male biased (Mead et al 1990, Sundell 2003. Disproportionately higher sampling probabilities of males through mortality are also known from other studies (eg Buchalczyk and Ruprecht 1977, Moors and Lavers 1981, Ansorge and Suchentrunk 2001, Lodé 2001. Since apparent mortality was no higher for males than for females, traffic killing and trapping is probably only responsible for a limited number of deaths in the live populations.…”