Species composition and community structure of small pest rodents (Muridae) in cultivated and fallow fields in maize‐growing areas in Mayuge district, Eastern Uganda

Abstract

Pest rodents remain key biotic constraints to cereal crops production in the East African region where they occur, especially in seasons of outbreaks. Despite that, Uganda has scant information on rodents as crop pests to guide effective management strategies. A capture–mark–recapture (CMR) technique was employed to study the ecology of small rodents, specifically to establish the species composition and community structure in a maize‐based agro ecosystem. Trapping of small rodents was conducted in permanent fallow land and cultivated fields, with each category replicated twice making four study grids. At each field, a 60 × 60 m grid was measured and marked with permanent trapping points spaced at 10 × 10 m, making a total of 49 trapping points/grids. Trapping was conducted monthly at 4‐week interval for three consecutive days for two and half years using Sherman live traps. Eleven identified small rodent species and one insectivorous small mammal were recorded with Mastomys natalensis being the most dominant species (over 60.7%). Other species were Mus triton (16.1%), Aethomys hendei (6.7%), Lemniscomys zebra (5.2%), Lophuromys sikapusi (4.8%), Arvicanthis niloticus (0.9%), Gerbilliscus kempi (0.1%), Graphiurus murinus (0.1%), Steatomys parvus (0.1%), Dasymys incomtus (0.1%), and Grammomys dolichurus (0.1%). Spatially, species richness differed significantly ( p = 0.0001) between the studied field habitats with significantly higher richness in fallow land compared with cultivated fields. Temporally, total species richness and abundance showed a significant interaction effect over the months, years, and fields of trapping with significantly ( p = 0.001) higher abundances during months of wet seasons and in the first and third year of trapping. In terms of community structure, higher species diversity associated more with fallow field habitats but also with certain rare species found only in cultivated fields. Synthesis and applications. Based on these findings, management strategies can be designed to target the key pest species and the most vulnerable habitats thus reducing the impact they can inflict on field crops.

Season and habitat affect diversity, abundance and reproductive state of small mammals near Lake Abaya, Ethiopia

“…As expected, diversity of the small mammals was lowest in the cropland compared to the non-crop habitats (including homestead). The results are in agreement with Demeke et al (2007), Mayamba et al (2019) and Shilereyo et al (2019) who also reported higher small mammal diversities in non-cultivated areas than in agricultural fields in Ethiopia (Arba Minch area), Uganda and Tanzania, respectively. The low small mammal species diversity in cropland can be ascribed to higher disturbance due to human activities including; land preparation (ploughing), weeding, thinning of young plants (particularly maize) and harvesting.…”

Influence of vegetation structure, seasonality, and soil properties on rodent diversity and community assemblages in west Mount Kilimanjaro, Tanzania

“…The habitat heterogeneity hypothesis explains that heterogeneous habitats support high species diversity due to increased microhabitats that provide more niches for coexisting species (August, 1983 ; Stein & Kreft, 2015 ). Heterogeneous habitats or habitat patches affect rodent diversity, abundance, and community assemblages through the provision of alternative microhabitats that serve as refuges and provide limiting resources to habitat generalists (Cramer & Willig, 2002 ; Mayamba et al, 2019 , 2020 ; Stein & Kreft, 2015 ). The influence of vegetation structure has been a central focus in the community ecology of small mammals including rodents (Cramer & Willig, 2002 ).…”

“…Heterogeneous habitats or habitat patches affect rodent diversity, abundance, and community assemblages through the provision of alternative microhabitats that serve as refuges and provide limiting resources to habitat generalists (Cramer & Willig, 2002;Mayamba et al, 2019Mayamba et al, , 2020Stein & Kreft, 2015). The influence of vegetation structure has been a central focus in the community ecology of small mammals including rodents (Cramer & Willig, 2002).…”

Perceptions on Barn Owls and Their Use in Rodent Control: A Case Study of Hwange District

“…Rodents are one the most numerous invasive species globally (Buckle & Smith, 1994), damaging maize crops ( Zea mays ) and other crops at different stages of growth, leading to great economic loss, threatening food security and the potential spread of diseases (Mayamba, et al, 2019). Rodents have mainly been controlled through the use of anticoagulants (which are hazardous to the environment and cause secondary poisoning on rodent-eating carnivores) (Mdangi, et al, 2016), traps (whose effectiveness is low as most of them catch a single rodent at any moment) and cats (which are low in numbers, hence their effectiveness on a large scale is low) (Mahlaba, et al, 2017).…”