Browsing by Author "Richard, Upendo"

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Microhabitat, altitude and seasonal influence on the abundance of non-volant small mammals in Mount Rungwe forest nature reserve
(Elsevier B.V., 2022) Richard, Upendo; Byamungu, Robert Modest; Magige, Flora; Makonda, Fortunatus B.S.
A study on microhabitat, altitudinal and seasonal influences on small mammal abundance in Mount Rungwe Nature Forest Reserve, Tanzania was carried out from March 2019 to February 2020 during the wet and dry seasons. Live traps were used in six grids and six transect lines for capturing small mammals at the low, mid, and high elevations (1700–2600 m.a.s.l.). Generalized linear models were used to examine the effects of microhabitat characteristics, altitude, and seasons on the relative abundance of small mammals. A total of 444 rodents and shrews were recorded on 4320 trap nights. Rodent species recorded included Beamys hindei, Cricetomys ansorgei, Dendromus insignis, Grammomys ibeanus, Graphiurus murinus, Lophuromys machangui, Praomys delectorum, and one shrew, Crocidura sp. Overall, P. delectorum was the most dominant species in all elevations, with 68.9% of all captures. Mid elevation had a higher abundance of small mammals (Estimate ± SE = 1.17 ± 0.49, Z = 2.37, p = 0.0176). Species abundance was influenced differently by elevation. While P. delectorum decreases with increasing elevation, L. machangui increases with an increase in elevation. Although overall small mammal abundance was not affected by microhabitat variables (Estimate ± SE = − 0.08 ± 0.13, Z = − 0.67, p = 0.5050), individual species (P. delectorum and L. machangui; Estimate ± SE = 0.13 ± 0.06, Z = 1.95, p = 0.05 and − 0.31 ± 0.09, Z = 3.34, p = 0.0008 respectively) were affected differently. While P. delectorum abundance showed a positive correlation and increased with an increase in PCA1 in GLM, L. machangui had a negative trend that shows they were affected differently. Small mammal abundance, on the other hand, was affected by season and, in particular, rain, with low abundance during heavy rains and dry cold periods (Estimate ± SE = 0.51 ± 0.14, Z = 3.6, p = 0.0003 and 0.3 ± 0.15, Z = 2.08 p = 0.04 respectively). In general, the results show that microhabitat parameters, elevation, and season influenced small mammals’ abundance in MRFNR. This outcome indicates that altering the microhabitat could have an impact on the small mammal assemblage and particularly their abundance. Thus, microhabitat, elevation, and season influence small mammal abundance and can be used as a proxy for evaluating the biodiversity of montane tropical small mammal communities.
Population ecology of small mammals in Mount Rungwe nature forest reserve
(Sokoine University of Agriculture, 2024) Richard, Upendo
Small mammals play significant ecological and economical role among many societies. Therefore, conducting ecological assessment of small mammals is crucial for maintaining functioning ecosystems and societal well being. The tropical mountains are characterised by diverse habitats, favourable environmental conditions, as well as abundant flora and fauna, including numerous endemic species. Among tropical mountains, Mount Rungwe Nature Forest Reserve (MRNFR) in southwestern Tanzania stands out as the second-highest mountain in the region, boasting its high diversity of flora and fauna, including several important IUCN endemic species such as Rungwecerbus kipunji, Cephalophus spadix and Galagoides sp. While there have been various studies on small mammals in Tanzania, the studies on mountainous small mammals remain limited, with most of them conducted in the northern part of the country and Eastern Arc mountains. This study aimed to understanding the ecology of small mammals in MRNFR which is situated at the intersection of the western, eastern and southern East Africa rift valleys. The study was conducted between 2020 and 2022 and involved data collection along an altitudinal gradient encompassing low-elevation, mid-elevation, and high-elevation with habitats low and mid montane forests, montane bamboo forests, montane bushland and montane grassland. Different methodologies were employed based on the stated specific objectives. The total of 300 Shearman traps, 60 pitfall traps, 132 snap traps and 18 Havahart traps were used. To determine the species composition, a combination of Sherman traps, pitfalls and Havahart traps was used along transects whereby five trapping nights were conducted at each elevation. Grids measuring 70 m X 70 m were established at each elevation to examine the influence of microhabitat parameters on small mammal abundance. Each grid contained 49 Sherman traps which were set over three consecutive nights. Microhabitat parameters, including vegetation and soil characteristics were collected using nested quadrant approach and soil core method. The data on population dynamics were obtained from permanent grids established over three consecutive days within a 24- month period at each elevation. For the purpose of diet analysis, the snap traps were placed in four transect lines at each elevation for six nights during both wet and dry periods and food categories were determined through macro-histological analysis of stomach contents. All collected species were identified using relevant keys and confirmed by sequencing the mitochondrial cytochrome b gene. A total of 3,183 individual small mammals comprised four families, eleven genera and twelve species were collected. Identified small mammals were Montemys delectorum, Crocidura luna, Lophuromys machangui, Grammomys cometes, Cricetomy ansorgei, Dendromus nyassae, Mysorex kihaulei, Crocidura olivieri, Hylomyscus arcimontensis, Beamys hindei, Graphiurus sp. nov. and Mus triton. A total of nine species were recorded during the wet season whereas ten species were recorded during the dry season. The results revealed that habitat characteristics and season significantly influenced small mammal richness, composition and diversity. The mid-montane forest exhibited the highest diversity compared to low-montane forests. Small mammal composition varied across habitats (Est ± SE = 3.36 ± 0.032, Z= 103.8, p < 0.001) with montane bushland showing significantly lower composition. Season and habitat significantly influenced species composition with montane bushland habitats having lower species composition and diversity during the dry season. The study further found out that small mammal abundance was influenced by elevation and season with mid-elevation and short rain period depicting the highest abundance. Elevation affected some species differently with P. delectorum decreasing and Lophuromys machangui increasing with an increase in elevation. On the contrary, Crocidura luna was not affected. Moreover, the results revealed that microhabitat parameters influenced abundance of individual species differently, thus indicating that altering the microhabitat could impact small mammal assemblage and abundance.Molecular information has revealed the presence of small mammal species such as Graphiurus sp. which was reported for the first time in this area. The study also demonstrated that habitat and microhabitat types, elevation gradient and seasonal variations strongly influence small mammal species abundance, diversity, richness and distribution at both the population level and individual species like P. delectorum and L. machangui. Some species such as L. machangui and P. delectorum are distributed in Northern and Southern Highlands, thus showing less influence from the boundaries between these two regions. However, the distribution of other species such as Graphiurus sp. and M. kihaulei is impacted by these boundaries. In particular, the study revealed the presence of endangered Myosorex kihaulei in MRNFR, which was previously believed to be endemic to Udzungwa Mountain only. Based on genomic analysis, the study documented novel Graphiurus sp. Such findings suggest the need to incorporate the observed species in the management plans of Southern Highland landscapes, particularly Rungwe Mountain, and consider the conservation of the noted endangered species. The findings also suggest that monitoring of species along the elevation gradient is crucial due to a greater diversity of species in Rungwe Mountains.