Abstract:
We investigated the composition of the diet of the multi-mammate mouse, Mastomys natalensis, within irrigated rice and
fallow field habitats at set time periods related to rice crop growth stages. In both habitats, vegetative plant material, i.e.
leaves, stems and seeds, were the most abundant components of the rodent’s diet, while other food types (invertebrates,
fruits) were observed only in low quantities. We conclude that vegetative plant material and seeds were the main types of
food consumed not only due to their relatively higher abundance in the environments under study but also because of the
highly specialised herbivorous/granivorous nature of the dominant rodent species, M. natalensis. Thus, the introduction
and expansion of continuous rice-cropping using irrigation in Tanzania is likely to be severely constrained by the presence
of M. natalensis. In our opinion, field hygiene, including the removal of alternative food resources and nesting sites for M.
natalensis near cropping areas, may help to both lower rodent population numbers and reduce immigration potential. Nonchemical
rodent control methods such as trap barrier systems developed for lowland irrigated rice in south-eastern Asia
should, we argue, be evaluated for their effectiveness under African conditions.
