SUA Pest Management Centre Collection

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    Community ecology of small mammals in the selous ecosystem, Tanzania
    (Sokoine University of Agriculture, 2022) Saanya, Aenea E.
    Historically, the protected areas in East Africa and possibly the rest of Africa were for conservation of large mammals. This inheritance approach has led to inadequate attention to other components of the ecosystems including small mammals which play a fundamental role in maintaining ecosystem health. This has resulted in inadequate information on their population dynamics in the tropics and miombo areas. Considering the current anthropogenic development trajectories, various studies have highlighted that, small mammals and other wildlife species are faced with a number of threats which include those related to management practices, economic development, and climate change. For example, as part of a wildlife habitat management tool, prescribed burning is practiced as a natural ecological phenomenon in miombo woodland that highly influences vegetation structure and composition with the aim of providing nourishing pasture. This practice has been reported to affect small mammal distribution and abundance. On the other hand, various studies have reported that climate change is posing an ever-increasing threat to wildlife management around the world making it a primary concern and driver of change. Climate change is also linked with increased zoonotic prevalence, especially with increased contact between humans and small mammals such as plague, hantaviruses pulmonary syndrome, and leptospirosis. Therefore, the current study aimed at investigating the community ecology of small mammals in the Selous ecosystem, Tanzania, as a basis for effective and holistic ecosystem management. The studies to assess the community ecology of small mammals in the Selous ecosystem, Tanzania, were carried out for two consecutive years from July 2018 to June 2020. The ecosystem constitutes a globally important example of vegetation types that is between Somali-Masai and Zambezian regional centers of endemism. The area possesses diverse flora with an estimated total of over 2 000 species with an exceptionally high variety of habitats that are ideal for small mammals. Specifically, the studies were conducted in the northern part of the Selous ecosystem which covers parts of Nyerere National Park (NNP) and Selous Game Reserve (SGR). The study aimed at addressing four key specific objectives; (i) establishing the diversity and distribution of small mammals (ii) determining the effects of prescribed burning on rodents‟ ecology (iii) estimating the relative home ranges and species – habitat association of small mammal species and, (iv) assessing the current and potential future distribution of small mammals in the Selous ecosystem. To address the specific objectives, various approaches were used; (i) for abundance, diversity, distribution, and home ranges estimations, four main habitats namely closed woodland, forest, seasonal riverine forest, and perennial riverine forest/thicket were selected; (ii) For effects of prescribed burning on rodents‟ ecology, prescribed burning was set twice during this study, on August of 2018 and 2019 and two grids in each area (burnt and unburnt) were used. Information of interest from this study include abundance, richness, diversity, age structure, sex ratio, breeding patterns, recruitment, and survival proportions; (iii) For current and potential future distribution of small mammals in the ecosystem, a total of 143 sites across nine selected habitats were used in different areas of the Selous ecosystem. In all approaches, Capture Mark Recapture (CMR) using medium-sized (LFA, 7.5 x 9 x 23 cm) Sherman‟s traps (H.B. Sherman Inc.) and random placement of Havahart traps (60 x 15 x 170 cm) were used. Trapping for estimating the current and potential future distribution of small mammals, two trapping nights were used from December 2018 to November 2019. In each selected site, a grid of 70 m x 70 m was established with seven parallel lines at 10 m intervals from each line and between traps, and in total, each grid had 49 stations. Species abundance was estimated using Minimum Number Alive (MNA) for the most captured species from the CMR data history. Shapiro_test function was used to test for normality of data in R software version 3.4. Kruskal Wallis, Wilcoxon, and Friedman's Chi-square tests were used to detect variation between and within habitats and seasons. Also, a non-normal generalized linear model with Poisson error distribution was performed by utilizing the “glm” function with link = log argument to compare mean differences of abundance between areas across seasons. In addition, robust regression by utilizing “rlm” function from MASS and “sfsmisc” packages in R software version 3.4 was used to assess the trend of abundance on monthly basis. To establish the small mammal species – habitat associations, a principle component was used. Ordination technique - Non-metrics Multi-dimensional Scaling (NMDS) using the Sorensen distance measure in vegan package using metaMDS function in R version 3.4. Age groups were compared using Wilcoxon.test for M. natalensis between burnt and unburnt areas. A generalized linear model with non-normal Poisson error distribution was used to compare mean differences between age groups between burnt and unburnt areas. Recruitment and apparent survival were computed from the CMR data history. On all occasions, the assumption was that there was an ability to detect a new and old individual through the marks applied. A generalized linear model (GLM) with logistic regression was used to compare recruitment and survival proportions data by using a built-in function called “family = binomial” in R software version 3.4 to explore the relationship between burnt and unburnt areas. For monthly trend variations, a robust regression model using “rlm” function from MASS and “sfsmisc” packages was used to assess monthly trends of capture proportions for recruitment and survival. Sex ratio and breeding patterns were compared using Wilcox.test between areas. A generalized linear model with binomial error distribution was used to assess the trends whereby proportions were treated as the response variables, while season and areas (burnt and unburnt) were used as explanatory variables. Relative home ranges were estimated from small mammals‟ relocation points from CMR history data. Relative home ranges were estimated using a Minimum Convex Polygon (MCP) using “adehabitatHR” package in R software version 3.4 using “mcp.area” function at 100% of all points. Home range overlaps were estimated using the “adehabitatHR” package by utilizing the “Kernel_overlap” function. Kruskal Wallis.test, one and two-way ANOVA were used to detect variation in home range across sex, habitat, and season. To assess the current and future distribution of small mammals in the Selous ecosystem, species occurrence (presence data) data and habitat parameters including elevation and location points were recorded from the field to enable mapping of current and projected suitable habitats. Additional data were obtained from the WorldClim dataset for bioclimatic data downloaded in raster (ASCII) format. Additional topographical data were obtained from Digital Elevation Models (DEM). Maxent algorithms were used to estimate the current and future distribution of small mammals in the Selous ecosystem. Models performance was evaluated using Area Under the Receiver Operating Characteristics Curve (AUC). QGIS v.3.10 was used to generate the distribution maps. The suitable habitat categories ranged between 0 and 1, with five classes values; <0.1 unsuitable habitat, 0.1 – 0.2 least suitable, 0.2 – 04 moderately suitable, 0.4 – 0.6 suitable habitat and > 0.6 highly suitable habitat. The results of this study showed that, abundance of Acomys ngurui was statistically significantly different between the four main habitats ( 2 = 12, df = 3, p = 0.007) and across seasons ( 2 = 6, df = 2, p = 0.049). Overall, forest habitat recorded the highest species diversity (H‟ = 2.065) and the lowest (H‟ = 1.506) diversity was recorded in perennial riverine forest/thicket. Dry seasons recorded the highest species diversity (H‟ = 1.65) and wet seasons the least (H’ = 1.445). On the effects of prescribed burning on rodents ecology, there were statistically significant different (W = 0.892, p = 0.0004) in abundance of A. ngurui between the burnt and unburnt areas and through seasons (Deviance = 2.644, df = 1, p = 0.021). Yet, for Mastomys natalensis, although its abundance increased after the prescribed burning events, the differences between the burnt and unburnt areas were not statistically significant (W = 344.5, p = 0.226), but significant difference between seasons (Deviance = 3.606, df = 1, p = 0.05). Species richness was higher in burnt areas than in unburnt areas suggesting burnt areas promote more species colonozitation compared to unburnt. Seasonality showed effects on richness with more species (5) appearing in the wet season in burnt areas than in unburnt areas. On the other hand, the highest species diversity (H‟ = 1.551) was recorded in burnt areas than in unburnt (H‟ = 0.759). On seasons, higher diversity in both wet and dry seasons was recorded in the burnt area (H‟ = 0.679 and 0.556 respectively) than in unburnt (H‟= 0.419 and 0.382 respectively) suggesting prescribed burning promotes higher diversity. On age groups, no statistically significant differences (Deviance = 3.507, df = 1 p = 0.061) between burnt and unburnt areas and across seasons (Deviance = 0.301, df = 1, p = 0.583) were recorded. On the other hand, the probability for both A. ngurui and M. natalensis survival (E = -0.481±11.233, z = -0.428, p = 0.669 and E = 0.377±7.044, z = 0.054, p = 0.957 respectively) and recruitment (E = 7.316±13.876, z = 0.528, p = 0.598 and E = 1.023±11.598, z = 0.088, p = 0.93 respectively) were not statistically significant different between burnt and unburnt areas. This was the same for breeding patterns and sex ratio suggesting that prescribed burning does not promote breeding and sex ratio variations in the Selous ecosystem. Overall, the results showed that prescribed burning as a management tool has effects on the abundance, richness, and diversity of rodents and not on specific demographic characteristics. On the home range, A. ngurui recorded the largest mean home range (1 087.58 m 2 ) than L. rosalia (831.55 m 2 ) and M. natalensis (166 m 2 ). Home range overlap was not statistically significant different between the two habitats but it was statistically significant difference across seasons in both habitats ( 2 = 33.5, df = 1, p = 0.000 and  2 = 46, df = 1, p = 0.000 respectively). Overall, most small mammals were associated with seasonal riverine forest which is characterized by high canopy and shrub cover while most murid species were associated with closed woodland with leaf litter and dead logs. The results of the current and future distribution of small mammals in the Selous ecosystem indicate that most of the current highly suitable habitats will be affected and small mammal species will be concentrated in a few areas within and outside the ecosystem. This study has provided important information for updating the current small mammal distribution maps as most of the small mammal species are reported for the first time from this area with molecular confirmation. Further, Grammomys selousi is being reported for the first time in the northern part of Rufiji River and South of Ruaha River. Considering the finding from this study, small mammal species abundance, diversity, and distribution are largely influenced by habitat types and seasonal variations at the community level and at individual species such as A. ngurui in the Selous ecosystem. This study has demonstrated that, overall, prescribed burning as a management tool favors the high abundance, richness, and diversity of small mammals. While for individual species, prescribed burning has shown varying effects both positive and negative. Acomys ngurui and M. natalesis have shown variations in the effect of prescribed burning on various demographic characteristics, suggesting that, although they share the same habitat, prescribed burning might affect them differently. The study has also shown a varied effect of habitats and seasons on the abundance of individual species suggesting that they are not uniformly affected. In relatively stable habitats with infrequent large herds of herbivores and prescribed burning, abundance has shown to be higher for A. ngurui while for L. rosalia and M. natalensis their abundance was higher in areas frequented by prescribed burning and large herbivores. In addition, this study indicated that large home ranges were recorded in the seasonal riverine forest for A. ngurui and L. rosalia which was relatively stable with infrequent disturbances while for M. natalensis it was different. Small mammal species have shown a high overlap within closed woodland suggesting shared resources with possible separation of time, i. e. crepuscular (L. rosalia) and nocturnal (A. ngurui and M. natalensis) and feeding behaviors with others being generalist such as M. natalensis and omnivorous (A. ngurui). Furthermore, most small mammals were associated with seasonal riverine forest than closed woodland suggesting that areas with limited activities of large mammals and management practices support more species while areas with varied degree of disturbances necessitate an adaptation to be able to survive. The study has further established the expected climate change effects, especially from the „business as usual scenario‟ (RCP 8.5) which is expected to shift the small mammal distribution in the Selous ecosystem both positive and negative based on specific species. The model suggests that most of the current highly suitable range will be affected and species will be forced to concentrate in a few areas within the ecosystem. It is important however to consider that, although the model predicted the observed distribution, there is a chance that this will depend on the species' capacity in adapting to the changing environment and the time expected for these changes to occur. All the species studied suggest being able to adapt to a dynamic habitat and can tolerate even the disturbed area. To address the gaps identified in this study, the following recommendations are made to the managers and policymakers of the protected areas; The information from this study call for an update of various management plans such as General Management Plans (GMP), Prescribed Burning Plan, Infrastructure Development/Management Plans and others to include the distribution of small mammals in the parks/reserves within the Selous ecosystem. Also, conservation managers are advised to maintain the current cycle of prescribed burning since any alteration might affect rodent species' population dynamics. Although no statistically significant variation in most demographic characteristics was vivid, at assemblage levels such as abundance, richness, and diversity, the effects were obvious. Furthermore, areas with low protection status such as Kilombero Game Controlled Area (KGCA) should be upgraded to Game Reserve/National Park standard to protect the important areas for species including small mammals' future strongholds. In addition, the management of different protected areas in the ecosystem are advised to include climate change as a key component in the development of General Management Plans (GMP). This may include a specific chapter to address climate change impacts including intensified patrol to reduce/avoid encroachment of any form and extension services related to the conservation of natural resources in the surrounding villages. Considering the importance of small mammals to the ecosystems, additional studies on their population dynamics are recommended to cover a wider part of the ecosystem including threatened, endangered, and/or rare/endemic species such as Grammomys selouis.
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    Does exploratory behavior or activity in a wild mouse explain susceptibility to virus infection?
    (Oxford university press., 2017-09) Makundi, Rhodes H.; Massawe, Apia W; Leirs, Herwig; Hughes, Nelika K; Broecke, Bram V; Borremans, Benny; Mariën, Joachim
    Exploration and activity are often described as trade-offs between the fitness benefits of gathering information and resources, and the potential costs of increasing exposure to predators and para- sites. More exploratory individuals are predicted to have higher rates of parasitism, but this relationship has rarely been examined for virus infections in wild populations. Here, we used the multimammate mouse Mastomys natalensis to investigate the relationship between exploration, activity, and infection with Morogoro virus (MORV). We characterized individual exploratory behav- ior (open field and novel object tests) and activity (trap diversity), and quantified the relationship between these traits and infection status using linear regression. We found that M. natalensis expresses consistent individual differences, or personality types, in exploratory behavior (repeat- ability of 0.30, 95% CI: 0.21–0.36). In addition, we found a significant contrasting effect of age on ex- ploration and activity where juveniles display higher exploration levels than adults, but lower field- activity. There was however no statistical evidence for a behavioral syndrome between these 2 traits. Contrary to our expectations, we found no correlation between MORV infection status and exploratory behavior or activity, which suggests that these behaviors may not increase exposure probability to MORV infection. This would further imply that variation in viral infection between individuals is not affected by between-individual variation in exploration and activity.
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    Relationships between seasonal changes in diet of Multimammate rat (Mastomys natalensis) and its breeding patterns in semi-arid areas in Tanzania
    (Cogent food and agriculture, 2018-09) Makundi, Rhodes H; Isabirye, Moses; Kifumba, David; Mdangi, Mashaka E; Nakiyemba, Alice; Leirs, Herwig; Belmain, Steven R; Mulungu, Loth S; Massawe, Apia W; Tarimo, , Akwilin J. P; Kimaro, Didas N; Mariën, Joachim; Mlyashimbi, Emmanuel C. M
    The diet and breeding patterns of Mastomys natalensis in semi-arid areas of Isimani division, Iringa region, Tanzania were investigated in maize fields and fallow land. The aim was to investigate the influence of diet on breeding patterns of M. natalensis. Removal trapping was used to capture rodents and analyse diet categories while Capture-mark-release trapping was used to investigate breeding patterns of female M. natalensis. Mastomys natalensis comprised 94% of the total capture, and the remaining 6% comprised of six other species. Statistical analysis of food preferences indicated that both vegetative materials and seeds were significantly higher in the overall diet of M. natalensis compared with other food materials. Significant differences in the proportions of vegetative materials and seeds were found between seasons (dry, wet), but not between habitats (fallow, maize). There was a clear seasonal pattern in the proportion of reproductively active females with peaks in April and troughs in October. The proportion of vegetative materials was highest during the wet season and correlated positively with reproductive activity, suggesting that vegetative materials contain certain compounds (e.g. 6-MBOA) that trigger reproductive activity in M. natalensis. The breeding activity of M. natalensis in semi-arid areas might, thus, be reduced by limiting access to fresh vegetative food (e.g. young sprouting grass).
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    Host use of bactrocera latifrons, a new invasive tephritid species in Tanzania
    (Entomological Society of America, 2010-02) Makundi, Rhodes H; Mziray, Hendry A; Mwatawala, Maulid; Maerere, Amon; Meyer, Marc DE
    Bactrocera latifrons (Hendel) is a pest of Asian origin, Þrst detected in Africa in 2006. We assessed the host utilization of this quarantine pest in Morogoro region, eastern central Tanzania, by collecting a wide range of cultivated and wild host plants of species belonging to Solanaceae and Cucurbitaceae from April 2007 to April 2008. Fruit were collected from 29 plant species and varieties (16 Solanaceae and 13 Cucurbitaceae) in all agroecological zones of Morogoro region. Twelve solanaceous fruit species yielded B. latifrons of which four are new host records: Capsicum annuum L. cov. longum A. DC., Capsicum chinense Jacq., Solanum sodomeum L., and Solanum scabrum Mill. Similarly, three cucurbitaceous fruit species provided positive rearings and are new host records: Citrullus lanatus (Thunb.) Matsum & Nakai, Cucumis dipsaceus L., and Momordica cf trifoliata L. The infestation rate and incidence of the pest was mainly high in the solanaceous hosts of nightshades (Solanum nigrum L. and Solanum scabrum) and African eggplants (Solanum aethiopicum Lam. and Solanum anguivi). In a host preference study involving limited number of cultivated solanaceous crops, S. scabrum was recorded as the most preferred host. The pest has been found to outnumber Bactrocera invadens (Drew et al.), Bactrocera cucurbitae (Coquillett), and Ceratitis capitata (Wiedemann) in most of the common solanaceous hosts.
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    Application of normalized difference vegetation index (NDVI) to forecast rodent population abundance in smallholder agro-ecosystems in semi-arid areas in Tanzania
    (ResearchGate, 2019-05) Hieronimo, Proches; Isabirye, Moses; Kifumba, David; Mulungu, Loth; Kimaro, Didas N; Makundi, Rhodes H.; Leirs, Herwig; Mulungu, Loth S.; Mdangi, Mashaka E.; Massawe, Apia W.
    This study aimed to evaluate the potential use of normalized difference vegetation index (NDVI) from satellite-­ derived remote sensing data for monitoring rodent abundance in semi-arid areas of Tanzania. We hypothesized that NDVI could potentially complement rainfall in predicting rodent abundance spatially and tem- porally. NDVI were determined across habitats with differ- ent vegetation types in Isimani landscape, Iringa Region, in the southern highlands of Tanzania. Normalized differ- ences in reflectance between the red (R) (0.636–0.673 mm) and near-infrared (NIR) (0.851–0.879 mm) channels of the electromagnetic spectrum from the Landsat 8 [Opera- tional Land Imager (OLI)] sensor were obtained. Rodents were trapped in a total of 144 randomly selected grids each measuring 100 × 100 m 2 , for which the corresponding values of NDVI were recorded during the corresponding rodent trapping period. Raster analysis was performed by transformation to establish NDVI in study grids over the entire study area. The relationship between NDVI, rodent distribution and abundance both spatially and tempo- rally during the start, mid and end of the dry and wet sea- sons was established. Linear regression model was used to evaluate the relationships between NDVI and rodent abundance across seasons. The Pearson correlation coefficient (r) at p ≤ 0.05 was carried out to describe thedegree of association between actual and NDVI-predicted rodent abundances. The results demonstrated a strong linear relationship between NDVI and actual rodent abundance within grids (R 2 = 0.71). NDVI-predicted rodent abundance showed a strong positive correlation (r = 0.99) with estimated rodent abundance. These results support the hypothesis that NDVI has the potential for predicting rodent population abundance under smallholder farming agro-ecosystems. Hence, NDVI could be used to forecast rodent abundance within a reasonable short period of time when compared with sparse and not widely available rainfall data.h
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    Ecology of rodent species in the Ukaguru mountains within the Eastern ARC mountains, Tanzania
    (Sokoine University of Agriculture, 2021) Ademola, Olaoluwa John
    Rodents, one of the diverse groups of mammals, are important contributors to biodiversity and good ecological indicators of habitat disturbance and their assessment is an important component of the study of forest ecosystems. Forested mountains in East Africa, which are home to diverse flora and fauna with sizeable endemics, include the Eastern Arc mountains (EAM) region and collectively with its adjacent lowland coastal forests recognized as one of the top 25 biodiversity “hotspots” worldwide. As conservation of any landscape requires knowledge of the available resources in the area, it is critical to study the rodents of the EAM due to the high degree of endemism in these mountain ranges and the rapid degradation of the remaining montane forests. However, research on rodents in sub-Saharan Africa has focused on pest species, and data on non-pest species is rare, however, needed for the implementation of effective conservation measures. The Ukaguru Mountains within the EAM are of particular interests because the forests of this range have received little/no attention on rodents and are facing alarming rate of anthropogenic disturbances such as grazing, firewood collection, tree/pole cutting and clearance of forest for agriculture which may impact on the diversity, population structure and demography of rodents. This study, therefore, aimed at understanding the ecology of the rodents, population and demographic parameters of the dominant species in disturbed and undisturbed habitats of the Ukaguru Mountains. There are two seasons in the landscape: wet and dry seasons; the wet season is October to May while the dry season is between June and September. Three methods were employed. In the first, the habitat association of the diversity and abundance of small mammals in the Ukaguru Mountains was assessed, by estimating the vegetation parameters using a Modified-Whittaker method and live-trapping of small mammals by Capture-Mark-Recapture (CMR) technique for three consecutive nights per month in farmland, disturbed and intact forests from June 2018 to February 2020. Two 70 m x 70 m grids, 600 m apart, were set in each habitat; each grid consisted of seven parallel lines, 10 m apart, and seven trapping stations per line, also 10 m apart (a total of 49 trapping stations per grid). The two grids in the disturbed forest were in proximity (50 m) to human settlements and farmlands and were characterized by cattle grazing, illegal hunting, tree cutting and wood collection. The two grids in the intact forests were devoid of human activities and were farther than 3 km away from disturbed forests. With the second method, the data derived from the CMR trapping in the disturbed and intact forests, was used to investigate the impact of anthropogenic forest disturbance on the abundance, breeding patterns and sex ratios and two demographic parameters: survival and maturation rate of the dominant rodent species i.e. Praomys delectorum. With the third method, removal trapping technique was used in the survey for rodents trapped for 13 months to determine the dietary composition of rodents in the landscape. Fifty snap (kill) traps were set separately in farm/fallow lands and forest habitats and trapping of rodents was conducted for three consecutive nights per month. Micro-histological analysis of the stomach contents of rodents collected from various habitats was carried out to determine the food categories. Small mammals were identified to species levels using relevant keys and confirmed by sequencing the mitochondrial cytochrome b gene. A total of 1196 individuals of small mammals comprising 13 species were captured from the CMR trapping in farmland, disturbed and intact forests; in the order of relative abundance, these are: P. delectorum (52.26%), Mus triton (21.07%), Mastomys natalensis (17.14%), Mus minutoides (2.93%), Lophuromys kilonzoi (2.26%), Crocidura hirta (1.59%), Beamys hindei (1.59%), Grammomys surdaster (0.59%), Graphiurus cf. raptor (0.17%), Lemniscomys rosalia (0.17%), Hylomyscus arcimontensis (0.08%), Pelomys fallax (0.08%) and Xerus sp. (0.08%). Mastomys natalensis, Mus triton and Praomys delectorum accounted for 90% of total captures. Mus triton and Mastomys natalensis were the most abundant in farmland with 46.75% and 42.77% of total captures respectively while P. delectorum accounted for 90% and 80% total captures in disturbed and intact forests respectively but the mean abundances in both habitats were not significantly different (p = 0.72). Species diversity and evenness in intact forest were much higher compared to disturbed forest. Principal component analysis (PCA) explained 87.70% of the variance with two factors. PCA 1 (67.47%) consists majorly of canopy cover, ground cover, shrubs and litter depth, with P. delectorum, B. hindei and L. kilonzoi loading positively. In the same component, herbs, Mastomys natalensis and Mus triton loaded negatively. Distance to human settlement contributed greatly to PCA 2 (20.23%) with G. cf. raptor, L. kilonzoi and C. hirta having greater than 0.5% loading. Mastomys natalensis and Mus triton associated with the herbaceous vegetation while P. delectorum correlated with litter depth and trees. The results suggest that vegetation and habitat disturbances are factors responsible for the observed diversity of small mammals in the Ukaguru Mountains. Analysis on sex ratios, population structure and breeding parameters were carried out on the dominant species i.e. P. delectorum in the two forest types. The population density of P. delectorum varied temporally with peaks attained in the wet seasons in both disturbed and intact forests. Population structure showed few juveniles in most months and sub- adults accounted for the population increases in the wet seasons in all habitats, high number of adults from the late wet season to the end of the dry season in disturbed forest but a greater number of adults in the wet season in intact forest. The sex ratios showed highly significant number of males in intact forest compared to disturbed forest (χ 2 = 10.71, df = 1, p = 0.001). The proportion of reproductively active individuals variedv temporally in both disturbed and intact forests while habitat disturbance showed no effect on the breeding activity of this species. Overall, these results suggest that rainfall and habitat disturbances as factors responsible for the varying sex ratios and population structure of P. delectorum in the landscape. Furthermore, the effects of habitat disturbance on abundance as well as two demographic traits: survival and maturation of P. delectorum were investigated. Abundance was estimated using the Minimal Number of animals Alive and subjected to a generalized linear mixed model. Survival and maturation probabilities were estimated using multi- event capture-recapture models using the software E-SURGE. There was no variation in abundance or maturation between intact and disturbed forests, but habitat type did affect survival. However, this effect was sex-dependent since female survival was higher in disturbed forests while male survival remained similar across the two forest types potentially due to differences in predation pressure or food availability between the two habitats. These results highlight the need for continuous demographic monitoring of P. delectorum in the EAM given that the increasing human population surrounding the landscape is leading to higher deforestation rates, and expansion of the pine plantation in the forest reserve. In the food analysis, Mastomys natalensis, Lemniscomys rosalia and Mus triton, seed/grain showed greater importance (> 35, > 55 and 60% respectively) whereas for Lophuromys kilonzoi (farm/fallow land), plant materials were more important (> 55%) than other categories. Seed/grains were more important (> 20%) in the diet P. delectorum, while plant materials were more important (> 45 %) in the diet of forest- dwelling L. kilonzoi. Food diversity for rodents in farm/fallow land was relatively low compared to forest dwelling rodents. Niche overlap between L. kilonzoi and P. delectorum was found to be relatively high. Given the interspersion of the forests with farmlands and their proximity, this may favour the establishment of farm generalists in the forests. The findings of the present study are of concern in conservation of this landscape and necessitate urgent conservation actions in this EAM block to limit the effects of anthropogenic activities in the landscape. As the human population surrounding the Ukaguru Mountains and their encroaching activities increase, continuous exploitation of the forests of this landscape should be discouraged as this was shown to modify the habitats of the small mammals, reducing their diversity and evenness and affecting other demographic parameters.
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    Population dynamics and breeding patterns of multimammate mouse, Mastomysnatalensis (Smith1834), inirrigated rice fields in Eastern Tanzania
    (Willey online library, 2012-06-21) Mulungu, L S; Ngowo, V; Mdangi, M; Katakweba, S A; Tesha, P; Mrosso, P F; Mchomvu, M; Sheyo, P M; Kilonzo, S B
    Multimammate mice are the most important vertebrate pests in Sub-Saharan Africa and are also reservoirs of many zoonotic diseases, including sylvan plague. This study investigated the population dynamics and breeding patterns of this mouse in irrigated rice cropping systems in eastern Tanzania. RESULTS:Themultimammatemouse,Mastomysnatalensis,populationvariedwithhabitatandmonths.Fallowlandhada more abundant population than rice fields. The highest population peak was observed during the dry season from July to October. Mastomys natalensis is sexually active throughout the year in the study area, although it reaches the highest level in June and December when rice is at the maturity stage. This suggests that breeding is highly influenced by the presence of a rice crop in both seasons. More juvenile individuals were recorded in August and September, indicating that they were produced in the previous breeding months. The sex ratio of M.natalensis was not skewed to either males or females, indicating that it was at parity. CONCLUSION: Rodent population dynamics during the study periods in all habitats indicated that high birth rates accounted for the rapid population growth and turnover. Regular control and sustainable operations are thus essential if rodent pest populations are to be kept with in tolerable limits.
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    Contribution of land use to rodent flea load distribution in the plague endemic area of Lushoto District, Tanzania
    (Sokoine University of Agriculture,, 2014-07-01) Hieronimo, Proches; Kihupi, Nganga I.; Kimaro, Didas N.; Gulinck, Hubert; Mulungu, Loth S.; Msanya, B. M.; Leirs, Herwing; Deckers, Jozef A.
    Fleas associated with different rodent species are considered as the major vectors of bubonic plague, which is still rampant in different parts of the world. The objective of this study was to investigate the contribution of land use to rodent flea load distribution at fine scale in the plague endemic area of north-eastern Tanzania. Data was collected in three case areas namely, Shume, Lukozi and Mwangoi, differing in plague incidence levels. Data collection was carried out during both wet and dry seasons of 2012. Analysis of Variance and Boosted Regression Tree (BRT) statistical methods were used to clarify the relationships between fleas and specific land use characteristics. There was a significant variation (P ≤ 0.05) of flea indices in different land use types. Fallow and natural forest had higher flea indices whereas plantation forest mono-crop and mixed annual crops had the lowest flea indices among the aggregated land use types. The influence of individual land use types on flea indices was variable with fallow having a positive effect and land tillage showing a negative effect. The results also demonstrated a seasonal effect, part of which can be attributed to different land use practices such as application of pesticides, or the presence of grass strips around fields. These findings suggest that land use factors have a major influence on rodent flea abundance which can be taken as a proxy for plague infection risk. The results further point to the need for a comprehensive package that includes land tillage and crop type considerations on one hand and the associated human activities on the other, in planning and implementation of plague control interventions. ________________________________________________________________________________
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    Comparative Study of Population Dynamics and Breeding Patterns of Mastomys natalensis in System Rice Intensification (SRI) and Conventional Rice Production in Irrigated Rice Ecosystems in Tanzania
    (Sokoine University of Agriculture,, 2016-01-07) Loth, Mulungu S; Lopa, Happy; Mdangi, Mashak E
    Mastomys natalensis is among the most important rodent pests in Sub-Saharan Africa. This study investigated the population dynamics and breeding patterns of this mouse in system rice intensification (SRI) and in conventional cropping systems in irrigated rice ecosystem in eastern Tanzania. The Mastomys natalensis population varied with years and season, but not with either SRI or conventional cropping system which would be expected as the all fields are in the same area. The highest population peak was observed during the dry season i.e., August to September. Breeding patterns of this rodent pest was not influenced by the cropping system or season, indicating that M. natalensis is sexually active throughout the year and does not be affected by the rice production systems. Regular control and sustainable operations, such as the use trap barrier system (TBS), are therefore essential if the populations are to be kept within tolerable limits.
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    Control of rodent pests in rice cultivation
    (Burleigh Dodds Science Publishing Limited, 2017-01-01) Brown, P. R; Htwe, N. M.; Mulungu, L.
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    Food preferences of the multi-mammate mouse, Mastomys natalensis, in irrigated rice habitats in Tanzania
    (Taylor & Francis, 2014-01-16) Mulungu, L S; Ngowo, v; Mdangi, M; Katakweba, S A; Tesha, P; Mrosso, F P; Mchomvu, M; Sheyo, P M; Kilonzo, B S
    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.
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    Ecology of major rodent pest species in maize and rice cropping system in Eastern Uganda
    (Sokoine University of Agriculture, 2020) Mayamba, Alex
    Rodent pests cause significant losses on several cereal crops but more so on maize and rice crops and thus pose a threat to the food security in Uganda and the rest of East Africa. In order to develop an effective management strategy against rodent pests, it is important to understand the diversity, breeding patterns and population dynamics and key demographic and ecological factors that regulate abundance and richness of the major rodent pest species. The above aspects formed the basis of this study’s objectives and provide the first detailed ecological information in Uganda’s rodent fauna in agro ecosystem environments. Two studies were conducted; in the first study a 2-year Capture Mark Release (CMR) rodent trapping was carried out in Mayuge district with grids placed in cultivated and fallow field habitats with the aim of establishing the species composition and community structure of small rodents, establish the population fluctuation and breeding patterns of key rodent species and establish the demographic traits including survival and maturation of key small rodent species in agro ecosystem environment. Sherman live traps were used to trap the small rodents on a monthly basis and traps set for 3 consecutive nights at each trapping session. Trapping was done on four permanent grids of 70*70 m2 measurement, with traps spaced at 10*10m making a total of 49 traps per grid. The second study was a trapping survey conducted across three districts with varying cropping systems and in the different seasons with the aim of establishing geo spatial ecological factors that influence rodent abundance. With the aid of Geological Information System (GIS) and remote sensing 20 sampling grids in each district were randomly identified using a randomization tool in Quantum GIS and were georeferenced and located with Global Position System machine for field rodent trapping. Landsat 8 images were acquired from the United States 3 Geological Survey (USGS) website for land use land cover characterization of the studied sites with further additional data collection on farm management practices. A total of 11 identified small rodent species and one insectivorous small mammal were recorded in both fallow and cultivated field habitats with the Mastomys natalensis being the most dominant in the following order; M. natalensis (60.7%), 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%). In terms of species turnover, spatially there was a significant difference (F1,6 =9, p=0.024) for the studied field habitats with fallow field habitats showing higher species turnover (6±1) compared to cultivated field habitat (4±1). Temporal species turn over (βT) also showed a significant difference (F5, 44 =18.819, p=0.0001) over the three years of the study, with her turnover in first 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. Higher diversity and species turnover in fallow fields could be explained by the characteristic nature of this habitat having better vegetation ground cover and less human interaction as compared to cultivated fields. On the other hand, the higher abundance ranking of M. natalensis in cultivated fields could be associated to its characteristic nature of being a good colonizer of disturbed habitats like farm lands. Based on these findings, management strategies ought to target M. natalensis and should be applied in both cultivated and fallow fields to prevent rodent infestation of crops. Further analysis on the population structure of the most dominant species i.e. M. natalensis was performed on the basis of seasonal changes in breeding patterns, population density and recruitment. 4 In terms of breeding, female animals were considered to be actively breeding when they had perforated vagina, enlarged nipples or pregnant whereas males were considered actively breeding in case of a visible scrotum. Data on recruitment of new individuals in the trappable population was also generated. Data on population density, percentage actively breeding animals and percentage recruitment were subjected to Generalized Linear Mixed Model with a Penalized Quasi Likelihood (PQL) method. Results on the breeding patterns showed continuous breeding of females throughout the year, with significantly higher percentages in second dry season (June-July), which was attributed to the observed availability of drying cereals and legumes from main planting season of the first wet season (March-May). Population density was observed to have peaked in the second wet season (September-November) and recruitment was significantly higher in the second dry season, with the later attributed to the increased animal breeding observed in the same period as reported above. Results have important applications on the timing of management practices, with possible recommendations to apply management options in the first wet season to prevent buildup of populations in subsequent seasons that can result into damaging populations. The demographic traits of M. natalensis in terms of maturation (the probability for a juvenile to become an adult) and survival (the monthly probability for an individual to survive from one month to the next) were also examined. CMR input data were subjected to specialized statistical modelling using software E-SURGE. Best model estimates showed higher survival of animals when rainfall was medium (300ml) to high (500ml) in the past month. The higher survival during periods of higher rainfall was attributed to possible increase in ground vegetation cover which is triggered by rainfall, thus animals are shielded from potential predatory animals. Maturation on the other hand was not 5 affected by rainfall, sex, habitat and population density a condition which could be attributed to the mixed cropping system in the study area thus offering a diversity of food sources for animal normal growth and development. The recapture probability was also modelled and higher recapture probability was observed in male animals compared to females. In the second study, data on small rodent population abundance and richness as the response variables were subjected to the Boosted Regression Tree (BRT) model analysis with several predictor variables including; Normalized Vegetation Index (NDVI), total monthly rainfall, soil texture class, farm management practices (crop field status, crop type etc.) to determine the relative importance of these variables on predicting small rodent abundance and richness. Overall modelling showed farm management practices (crop field status) was the most important factor for predicting both abundance and richness. This could be attributed to the additive influence of both crop and field states which have influence on food availability and suitable vegetation ground cover for animal habitation. Other important factors including NDVI, crop type and soil texture (in particular soil silt particle proportion) were important in predicting abundance and richness. In conclusion this study has provided important information on several aspects of the ecology of rodents associated with agro ecosystems, knowledge that can help in the development of adaptive pest management strategies such as concentrating efforts on M. natalensis species, timing control in the first wet season, promotion of collective control even in non-cereal crops in Uganda and other regions with similar climatic and farming systems.
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    Effect of synthetic hormones on reproduction in Mastomys natalensis
    (Journal of Pest Science., 2018) Massawe, A. W.; Makundi, Rhodes H.; Zhang, Z.; Mhamphi, G.; Liu, M.; Jun Li, H.; Belmain, S. R.
    Rodent pest management traditionally relies on some form of lethal control. Developing effective fertility control for pest rodent species could be a major breakthrough particularly in the context of managing rodent population outbreaks. This laboratory-based study is the first to report on the effects of using fertility compounds on an outbreaking rodent pest species found throughout sub-Saharan Africa. Mastomys natalensis were fed bait containing the synthetic steroid hormones quinestrol and levonorgestrel, both singly and in combination, at three concentrations (10, 50, 100 ppm) for 7 days. Consumption of the bait and animal body mass was mostly the same between treatments when analysed by sex, day and treatment. However, a repeated measures ANOVA indicated that quinestrol and quinestrol + levonorgestrel treatments reduced consumption by up to 45%, particularly at the higher concentrations of 50 and 100 ppm. Although there was no clear concentration effect on animal body mass, quinestrol and quinestrol + levonorgestrel lowered body mass by up to 20% compared to the untreated and levonorgestrel treatments. Quinestrol and quinestrol + levonorgestrel reduced the weight of male rat testes, epididymis and seminal vesicles by 60–80%, and sperm concentration and motility were reduced by more than 95%. No weight changes were observed to uterine and ovarian tissue; however, high uterine oedema was observed among all female rats consuming treated bait at 8 and 40 days from trial start. Trials with mate pairing showed there were significant differences in the pregnancy rate with all treatments when compared to the untreated control group of rodents.
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    Happily together forever: temporal variation in spatial patterns and complete lack of territoriality in a promiscuous rodent
    (2013-08-31) Borremans, B.; Hughes, N. K.; Reijniers, J.; Sluydts, V.; Katakweba, A. A. S.; Mulungu, Loth S.; Sabuni, C. A; Makundi, Rhodes H.; Leirs, H.
    The availability of resources, their effect on population density and territoriality, and the ways in which these factors are interwoven with mating systems are important determinants of small mammal space use. It is often difficult to study these patterns in an integrated way, however, especially because long-term data are needed but not readily available. In this paper, we investigate effects of population density, season and breeding status on home range patterns of the promiscuous rodent Mastomys natalensis using monthly capture-mark-recapture data collected over 17 years in a 3-ha grid. Home ranges were estimated using minimum convex polygons bounded by trap locations, and home range overlap and visitation rates were calculated as a measure of territoriality. As higher population densities coincide with increased resource availability, we predicted that home range sizes would correlate negatively with density. Furthermore, as M. natalensis is promiscuous and population densities are generally high, we predicted that territoriality would be low, and home range overlap would therefore be high. Contrary to expectations the home ranges of female adults increased with population density, although those of male adults and subadults followed the expected decrease. Home range overlap and visitation rates were generally high, and increased significantly with population density. More importantly, they were never lower than those of simulated datasets consisting of randomly moved home ranges. These results therefore suggest that M. natalensis displays a complete lack of territoriality that is rarely seen in small mammals but still meets predictions based on knowledge of density and mating system.
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    Survival and recruitment of the multimammate mouse, Mastomys natalensis (smith 1834), in a rice agro-ecosystem
    (Mammalia, 2016) Mulungu, L. S.; Ngowo, V.; Mdangi, M. E.; Katakweba, A. S.; Tesha, P.; Mrosso, F. P.; Mchomvu, M.; Massawe, A. W.; Monadjem, A.; Kilonzo, B.; Belmain, S. R.
    We investigated the recruitment and survival of the multimammate mouse, Mastomys natalensis, within irrigated rice and fallow field habitats at different time periods related to rice crop growth stages. Capture-Mark- Recapture data were collected for M. natalensis each month from June 2010 to May 2012, and both recruitment and survival were estimated in relation to land use (irrigated rice or fallow field) within the agro-ecosystem. Higher recruitment and survival were observed in rice fields than in fallow fields suggesting the relationship was compensatory when there was a higher quality food resource. In terms of management, farmers in the study area should implement management strategies in rice fields at both transplanting and maturity stages of crop growth in order to maintain recruitment and survival at low levels.
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    Control of rodent pests in maize cultivation: the case of Africa
    (Burleigh Dodds Science Publishing Limited, 2017) Mulungu, L. S.
    Rodents cause serious problems to human communities in Africa as a result of their involvement in the spread of diseases (Katakweba et al. 2012) and in the losses of crops through direct consumption (Mulungu et al. 2003; Bekele et al. 2003) and spoilage (Mdangi et al. 2013). For example, Taylor (1968) reported 20% damage to maize crop after the outbreak of rodents in Western Kenya. Earlier reports (Taylor 1968) on economic losses due to rodents in Kenya indicated 20–30% damage to maize crops, and a 34–100% loss during rodent outbreaks. In Ethiopia, it has been estimated that rodents consume up to 26.4% of maize crop in most years (Bekele et al. 2003). In Northern Ethiopia, surveyed farmers estimated 9–44% pre-harvest yield losses in annual production of cereal crops due to rodent attacks (Meheretu et al. 2010), while Central Ethiopia showed 26.4% loss of yield in maize (Bekele et al. 2003). In Tanzania, rodents are estimated to cause on average 15% yield loss (Makundi et al. 1991), which would mean the loss of around 382 673 tonnes per year of the actual yield (FAO statistics 2014). This amount of maize, with an estimated value of US$42.5 million (at US$11.1 per 100 kg bag of maize), would be enough to feed 2.1 million people for a whole year (at about 0.5 kg/day/person). However, in many parts of Africa, this figure has risen dramatically over the last few years, most noticeably in places where rodent outbreaks occur (Mwanjabe et al. 2002; Taylor and Green 1968, 1976). Today
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    Comparative and functional morphology of the middle ear in Zambezian mole-rats (Coetomys – Cryptomys, Bathyergidae)
    (Belg. J. Zool, 2005-12) Leirs, Herwig; Makundi, Rhodes H.; Davis, Stephen; Lange, Simone; Burda, Hynek; Assogbadjo, A.E.; Codjia, J.T.C.; Sinsin, B.; Ekue, M.R.M.; Mensah, G.A.; Mgode, G.F.; Mhamphi, G.A.; Katakweba, A. W.; Paemelaere, E; Willekens, N.; Leirs, H.; Machang’u, R.S.; Hartskeerl, R.A.
    Within the family Bathyergidae, the genus Coetomys (Cryptomys) is the most speciose. However, an unambiguous morphological or morphometrical species diagnosis has not been feasible to date. The middle ear structures involved in sound transmission were examined and measured in six species of Zambezian mole-rats of varying body sizes : Coetomys amatus, C. anselli, C. darlingi, C. kafuensis, C. mechowi and C. whytei. Compari- sons revealed many differences in the shape of the middle ear ossicles allowing species differentiation. Bullar vol- ume, eardrum area and cross-sectional area of the bony meatus were positively correlated with body size (as repre- sented by condylo-basal length) whereas the size of middle ear ossicles was rather independent of body size. Middle ears shared typical features with those found in low-frequency hearing mammals. Contrary to the findings in heter- omyids and the Spalax ehrenbergi species complex, within the genus Coetomys, those species occupying more mesic habitats had more efficient tympano-ossicular systems (suggesting more sensitive hearing) than species from drier habitats.