Polyandry and polygyny in an African rodent pest species, Mastomys natalensis

摘要

Males and females use different mating strategies and seldom have these strategies been studied on the field for cryptic rodent species. We studied the breeding strategies of both males and females of the sub-Sahara African rodent pest species, Mastomys natalensis, in the field using capture removal and capture-mark-recapture techniques combined with microsatellite analyses. In total, 36 litters (359 young) and 94 candidate fathers were genotyped. Multiple paternity (more than one male per litter) occurs frequently in all sampled grids (> 47% of all litters). Paternity assignment success rates are relatively high (mean 69%). Males are polygynous, but this is less frequent than female polyandry. Large differences in male reproductive success exist with a large part of the male population without offspring in our sample. Larger males father significantly more offspring. Spatial analyses do not show a strict spatial organisation. Our data suggest male M. natalensis roam around to mate with as many females as possible, while females also mate with several males to produce litters fathered by several males. This species could be an interesting candidate for testing virally vectored immunocontraception as a pest management technique due to the promiscuous mating and high frequency of sexual contacts.