African Zoology
The breeding dynamics of three species of rodents, Mastomys natalensis, Aethomys
chrysophilus and Gerbilliscus vicina were investigated in a seasonal environment (wet versus
dry) in Berega in the eastern parts of central Tanzania. Berega has a distinct unimodal rainfall
pattern, with most rainfall from November to April/May. We hypothesized that breeding of
rodents in central Tanzania would be confined to the wet season, when unlimited resources
would be available for reproduction. We provide evidence of breeding discontinuity in the
three species, showing that breeding was seasonally restricted to the wet season and early in
the dry season. The observed discontinuity could largely be ascribed to variation in primary
productivity between the wet and dry seasons. Reproductively active females were found in
the population as early as November, a month into the rainy season, but when early rains
occurred, some individuals were already breeding in October. Breeding was more intensive in
the latter part of the wet season (March–May) and completely ceased during the dry season.
For M. natalensis, survival was highest in the wet period and low in the dry season. The study
provides knowledge on the breeding dynamics of rodents in central Tanzania, which can help
farmers to take proactive rodent management decisions to prevent high rodent densities and
reduce crop damage in the fields. Application of control measures by the community early in
the season when populations of reproductive females is lowest will be most rewarding.