A study aimed at assessing the structure of rodent and shrew assemblages inhabiting a degradation gradient while considering rainfall patterns was conducted in one of the few remaining lowland tropical forests in Eastern Africa. We collected a unique dataset of 1411 rodents and shrews, representing 24 species (19 rodents, 5 shrews). The most abundant species alternated in dominance as species abundance significantly fluctuated across the study period following a degradation gradient, While only generalist species were observed near the degraded forest edge, habitat specialists such as Deomys ferrugineus, Malacomys longipes and Scutisorex congicus, were observed in the primary forest interior suggesting a significant association between species and their associated habitats and habitat attributes. There was also an observed correlation between rainfall patterns and species abundance. Capturing more species in adjacent fallows and along the degraded forest edge suggests that many species are able to live in degraded habitats that offer a variety of food resources. The continued pressure on forest resources, however, may lead to changes in habitat structure. This, coupled with the dependence of forest ecological functions on rainfall, which is typically not the case, may ultimately cause the local extinction of highly specialized but less adaptable species.

Data was collected in Mabira Central Forest Reserve for 12 months between August 2018 and December 2019. Data were intermittently collected (with a one-month break after two months of data collection) along a gradient of habitat degradation that included a primary forest interior, a degraded forest edge, and fallows, gardens, sugarcane plantations, homesteads close to the forest, collectively referred to as adjacent habitats. Rodents and shrews were trapped using Sherman traps Morphometric measurements were taken from every captured specimen including the total length (TL), tail vertebrae length (TV), hind foot length (Hf), ear length, and weight (Wt). All measurements were recorded in millimeters and weight in grams. All specimens collected were kept as wet specimens in 75% ethanol and kept as vouchers in Makerere Zoological Museum. Collected specimens were identified to species using morphometric measurements cross references with published identification guides (Brambell 1973, Delany 1975, Thorn & Kerbis 2009, Monadjem et al. 2015) For selected individuals of each morphotype, identifications were confirmed by sequencing of partial mitochondrial cytochrome b gene (i.e. DNA barcoding) from 96% ethanol-preserved samples at the Institute of Vertebrate Biology (IVB) of the Czech Academy of Sciences.