Soil type influences population dynamics and survival of the Multimammate rat (Mastomys natalensis) in semi-arid areas in Tanzania

Rodent population dynamics and survival in semi-arid areas of Tanzania were investigated in fallow land and maize fields (land use) and two soil types (sandy loam and black clay). Capture-Mark-Release (CMR) methods with four 60 m X 60 m trapping grids, (two in maize and two in fallow mosaic fields) were used. Mastomys natalensis comprised >94% of the total captures, and the remaining six percent comprised 11 other small mammals species. The number of M. natalensis was higher in sandy loam (7.82) than in black clay (2.89) soils and higher in fallow land (40.25) than in maize fields (26.49). Highest rodent abundance was observed during the dry season (from June to August) of each year, while the lowest abundance was recorded during the wet seasons (February to April) in both habitats. A significantly different proportion of reproductively active female M. natalensis was observed in sandy loam than in black clay soils. It was observed that female M. natalensis are found to breed almost throughout the year. Survival of M. natalensis differed between dry and wet seasons and was lower in clay soils during the wet season compared to sandy soils. However, there were no significant effects with respect to interactions between soil type and land use, soil type and month, land use and month and soil type, land use and month. Management strategies should therefore, be aimed at emphasizing the importance of targeting March-May in order to interrupt reproduction and young rearing