Spatial and temporal variation in small mammal abundance and diversity under protection, pastoralism and agriculture in the Serengeti Ecosystem, Tanzania (original) (raw)
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The overall objective of this study was to understand the influence of anthropogenic disturbance on the abundance, diversity, richness and distributionof small mammals, and in Wildlife Management Areas of the Ruvuma landscape: Mbarang'andu, Kimbanda, Kisungule in Namtumbo District and Nalika and Chingoli in Tunduru District. The survey was conducted using standard live Sherman trap (23 x 8 x 9 cm) andplastic bucket pitfall traps (33.3cm high x 30cm diameter). A total of 187 individual small mammals were captured, including 17 species in 16 genera and five families. Chingoli had the least number of species with five species while Kimbanda accommodated the highest number of species (with 10), closely followed by Kisungule with 9 species. Species diversity was significantly different between areas of high and low anthropogenic disturbance. Therefore we suggest that human resources and funds should be available to safe guard from any environmental degradation for the benefit of present and future generation.
International Journal of Biodiversity and Conservation
Habitat type and their vegetation composition play important role in determining the abundance and diversity of animals including small mammals, hence any change in habitat type will influence their abundance and spatial distribution. This study aimed at investigating the influence of habitat types (that is, Wetland grassland, Miombo and Vachellia woodlands) on small mammal abundance, diversity, and richness in the Usangu area, in southern part of Ruaha National Park, in Tanzania. Sherman and pitfall plastic bucket traps were employed both for trapping small mammals. A total of 92 small mammals were captured in 2124 trap nights giving 13% trap success representing two families, namely, Muridae (6 species) and Soricidae (1 species). Furthermore, trap success differed among habitat types with the highest being in wetland grassland. Species diversity was higher in Vachellia woodlands compared to other habitat types. It would therefore seem that wetland grassland and Vachellia woodland habitats are very crucial in maintaining small mammal abundance and diversity in Usangu Area. Therefore, future management plan should incorporate these refuge habitats for continued existence of small mammals in Usangu. Further study is warranted in wet season in order to have comparison information that will assist in management of small mammal in Usangu.
International Journal of Biodiversity and Conservation, 2020
This work examined population demography and reproductive seasonality among small mammals under protection, pastoralism and agriculture in the Serengeti Ecosystem in 2017 and 2018. Small mammals were trapped to quantify variation in the proportions of actively breeding individuals, juvenile recruitment and adult sex ratio across land use types and seasons. Breeding peaked in the wet season, reflecting a corresponding underlying peak in resource availability and quality. The mean community proportion of reproductively active individuals was greater for females (60%) than males (40%) and under pastoralism than protection or agriculture. Juvenile recruitment was the highest in the pastoral land in the dry season. Adult sex ratio was biased towards males across all land use types and seasons but towards females in the pastoral than the agricultural land. This concurs with the Trivers-Willard hypothesis that nutritionally stressed females should produce more female offspring. Two generalist and pest species (Mastomys natalensis and Arvicanthis niloticus) dominated the pastoral areas indicating human disturbance. Anthropogenic activities degrade habitats, altering population demographics and promoting habitat generalists and pest species. Protection promotes habitat intactness and reduces opportunistic pests typically abundant in disturbed landscapes. Consequently, enhancing conservation around protected areas can improve diversity and control the abundance of opportunistic pest species.
Biodiversity and Conservation, 2012
Even though human induced habitat changes are a major driver of biodiversity loss worldwide, our understanding of the impact of land use change on ecological communities remains poor. Yet without such information it is difficult to develop management strategies for maintaining biodiversity in the face of anthropogenic change. To address this gap, we explored how land use practices impacted species richness in a mammalian community in northern Tanzania. Using camera traps, we estimated the number of mammalian species inhabiting three land use types subjected to increasing levels of anthropogenic pressure: (1) Tarangire National Park, (2) pastoral grazing areas; and (3) cultivated areas outside the park. Results showed that land use practice is correlated with different levels of species richness. Interestingly, mammal species richness was highest in the grazing areas and lowest in cultivated areas. When we focused our analyses on carnivores, we found little significant difference in species richness between the park and pastoral grazing areas, however, carnivore richness were significantly lower in the cultivated areas. We found no significant link between species body weight and presence in the three areas considered. Altogether, our results show that biodiversity conservation can be achieved outside national parks, with pastoral grazing areas holding a significant proportion of mammal communities; however increasing cultivation of pastoral rangelands may represent a major threat to mammalian communities.
This study compared the ecology of small mammals in natural and agricultural habitats of Mbeya Range Forest Reserve and Idunda in Mbeya City. Small mammal sampling through the use of Sherman-style and funnel traps and measurements of micro-habitat characteristics associated with small mammals were done for 42 days. Each study site had 4 sub-sites. Seven rodent species and one shrew were captured and Mastomys natalensis was the most abundant while Rattus rattus was the least abundant species. Species diversity varied among the study areas' sub-plots. With exception of Lophuromys spp. positive correlation with bare ground, all other small mammals' individual abundances correlated negatively with the measured micro-habitat characteristics. There was no significant difference between Sherman-style and funnel trap efficiency in catching small mammals. Results further suggested that both agricultural and natural areas are favorable habitat for small mammals. The study recommends a research to compare the ecology of small mammals in the two habitats in different seasons of the year; other important factors for small mammals distribution and abundance such as water, predators, food availability, soil characteristics, and interactions with human being.
Biological Conservation, 2019
The effectiveness of Protected Areas (PAs) in reducing hunting pressure on mammal populations in tropical forests has rarely been examined at a community-wide level. In African forests, commercial and subsistence hunting are widespread, but assessments of mammal abundance and distribution patterns are often lacking. We investigated patterns of occupancy and abundance for 27 species of medium-to large-bodied mammals (>2 kg) within Tanzania's Udzungwa Mountains Afromontane forests, a global biodiversity hotspot. We sampled 22 forest sites within 10 forests under varying degrees of protection, elevation, distance to extractive communities, and levels of law enforcement. We sampled 251.7 km of recce line transects during dry seasons (July-November) between September 2007 and July 2010. We found a strong positive effect of protection status on species richness and on encounter rates of the most commonly encountered species. Consistent with the levels of resources and enforcement within each PA category, there was a significant progression in species richness and abundance from Forest Reserves through Nature Reserves to sites within Udzungwa Mountains National Park. Protective status closely reflected levels of disturbance. Snaring activity, and distance to ranger posts were identified as significant predictors of overall species richness and encounter rates for mammal species, including endemics. The species-area relationship for our study species was found to be largely overridden by levels of protection. Our findings demonstrate PA effectiveness in Afromontane forests and reinforce concerns over hunting pressures particularly the threat posed by snares.
Environment and Natural Resources Research
The need for rapid development in developing countries has led to establishment of major public infrastructure even in biodiversity rich protected areas. Mikumi National Park in central Tanzania is traversed by five such major infrastructures namely an optic fibre, a busy public road, an oil pipeline, power lines and railways. We assessed diversity and abundance of small terrestrial mammals of the order Eulipotyphla and Rodentia as indicator groups in relation to impacts of such infrastructure. Animals were live trapped during wet (February-April) and dry (July- September) seasons in 2018 from three established plots along the three transects set perpendicular to each of the four infrastructures. In 10102 trap nights, we captured 453 small mammals of nine species of which Mastomys natalensis constituted 75.4 % of total catch. Diversity and abundance varied between seasons, infrastructure and plots location. Dry season had significantly higher diversity than wet season and the railwa...
Ecological Drivers of Habitat Use by Meso Mammals in a Miombo Ecosystem in the Issa Valley, Tanzania
Frontiers in Ecology and Evolution
Vast stretches of East and Southern Africa are characterized by a mosaic of deciduous woodlands and evergreen riparian forests, commonly referred to as “miombo,” hosting a high diversity of plant and animal life. However, very little is known about the communities of small-sized mammals inhabiting this heterogeneous biome. We here document the diversity and abundance of 0.5–15 kg sized mammals (“meso-mammals”) in a relatively undisturbed miombo mosaic in western Tanzania, using 42 camera traps deployed over a 3 year-period. Despite a relatively low diversity of meso-mammal species (n = 19), these comprised a mixture of savanna and forest species, with the latter by far the most abundant. Our results show that densely forested sites are more intensely utilized than deciduous woodlands, suggesting riparian forest within the miombo matrix might be of key importance to meso-mammal populations. Some species were captured significantly more often in proximity to (and sometimes feeding on)...
Land-use change is considered a major driver of biodiversity loss. In the western part of the Tarangire-Manyara ecosystem, we assessed large mammal species richness along a land-use gradient (national park, uninhabited pastoral area and settled pastoral-and farmland). We found the highest species richness in the national park and in the pastoral area and lowest species richness in the settled and farmed area. There was little evidence of seasonal changes in species diversity. Except for top-order carnivores, all functional feeding guilds were still represented in pastoral and settled areas. Although we did not find significant differences in body mass distributions and species' representation of feeding guilds between the study sites, there was a trend that omnivores, mesopredators and top-order carnivores tended to occur at lower species richness in agricultural areas than in the pastoral and fully protected areas. These results indicate that areas used for livestock keeping can maintain high wildlife species richness and that direct and indirect effects of agricultural and settlement expansions are the main drivers of species richness loss in the Tarangire-Manyara ecosystem and possibly other African savannah ecosystems. These results are useful for informed land-use planning that aims to maintain species diversity and ecological connectivity between protected areas.
2005
The Lulanda forest cover a portion of the Udzungwa mountains in Mufindi district, Tanzania, ranging from 1480 -1640 meters above sea level. The forest consists of three forest patches dominated by Parinari excelsa and a corridor between two of them that is being regenerated to a forest under the help of the Tanzania Forest Conservation Group (TFCG). A capture-mark-recapture study was carried out to document the small mammal species found in Lulanda forest patches and corridor. There is a considerable difference in small mammal species composition between the montane forest and the corridor with a higher diversity in the corridor.