Spatio-temporal abundance and breeding patterns of ar vicanthis n1loticus and mastomys na talensis in western serengeti, Tanzania

This study investigates the abundance and breeding patterns of two rodent species, Arvicanthis niloticus and Mastomys natalensis, in the Western Serengeti, Tanzania. Sherman live traps were used for trapping in the three sites, each with three different levels of conservation status (Open areas, Game reserve and National Park). Observations were made also on species diversity and ectoparasites load of the two rodent species. A total of 2217 individuals were caught in a capture-mark-recapture (CMR) study, of which 994 were A. niloticus and 634 were M. natalensis; other rodent species and insectivores constituted the remaining 589 individuals. Sixteen (16) rodent and two (2) insectivore species were caught. Diversity increased towards the protected areas most probably because of the high vegetation diversity. Within sites, as the richness of vegetation increased the diversity of rodents increased as well. Breeding activity peaked during the wet season. The activity in males (scrotal/enlarged testes) and females (lactating, perforate and pregnant) increased soon after the onset of the rains. A. niloticus were abundant in the wooded grasslands of protected areas whereas M. natalensis were more prevalent in the open areas. Both rodents harboured ectoparasites, mainly fleas, mites, ticks and lice, in varying quantities. A. niloticus carried mostly lice while M. natalensis carried mostly mites. Abundance and breeding of these two species was found to be generally higher in the wet season, the increase was likely caused by improved habitat and food availability.