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Threats to ecosystems are ever increasing from different drivers mostly being linked to anthropogenic activities. This has brought about various measures to restore/protect the wildlife in these areas. Considering the background of most protected areas in East Africa, small mammals have been given least attention, compared with large mammals, although they play a fundamental role in maintaining ecosystem health. It is therefore necessary to understand how small mammals are distributed in any given ecosystem as a baseline information to enable holistic and informed management. We investigated the diversity and distribution of small mammals in the Selous ecosystem, Tanzania. Two methods were used; Capture Mark Recapture (CMR) using grids of 70 m x 70 m and random placement of havahart traps in the selected habitats. Between July 2018 and June 2020, a total of 887 individuals belonging to 20 species were captured in 28 224 trap nights with 3% trap success. The small mammal species captured consisted of rodents (91.8%), Macroscelidea (3.9%), Carnivores (2.4%) Eulipotyphla (1.6%), and Primates (0.3%). Acomys ngurni(36%) and Aethomys chrysophilus(17%) were the most captured species, whereas Atilax paludinosus(0.23%), Helogale pervula(0.23%), Rattus rattus(0.23%) and Galerella sanguinea(0.11%) were the least contributing species. Acomys nguruiand Lemniscomys rosaliawere the most distributed species occurring in all four habitats, whereas Cricetomys ansorgei, Rattus rattus, Mungos mungoand Genetta genettahad low occurrence. Grammomys selousiis reported for the first time in the northern part of the Rufiji River. Acomys ngurniabundance differed significantly (χ2= 12, df = 3, p= 0.007) between the four habitats being higher in the seasonal riverine forest and across seasons (χ2= 6, df = 2, p= 0.049), with more individuals occurring in the wet season. The Sable Forest habitat had the highest species diversity (H' = 2.065) and the lowest diversity (H' = 1.506) was recorded in perennial riverine forest/thickets. The highest species diversity (H' = 1.65) was recorded in the dry season and the lowest diversity in the wet season (H' = 1.445). Most small mammals were associated with seasonal riverine forest than other habitats. Overall, the results from this study show that, the park is rich in small mammal fauna. Therefore, considerations in updating the General Management Plan (GMP) and other plans to include the small mammals in the park management actions is recommended.

Multimammate mice (Mastomys natalensis) are a key rodent pest species to cereal crop production in Sub-Saharan Africa. This study aimed at generating information on the population fluctuation and breeding patterns of M. natalensisin a maize dominated agro-ecosystem in the Mayuge district, Eastern Uganda. The area is characterised by a bimodal rainfall pattern with rains in the periods March to May and August to November. A Capture–Mark–Recapture study was established in cultivated and fallow field habitats with, in each habitat, two plots of 60 m by 60 m with 49 evenly spaced trapping points. Trapping was conducted monthly for three consecutive nights, and the study extended from January 2016 to June 2018. A Generalised Linear Mixed Model analysis showed significantly higher population density estimates (β = 0.69, p< 0.0001) in fallow land compared to cultivated fields, and also significantly higher density estimates( β = 0.75, p= 0.006) in the first wet season and lowest in the first dry season. The percentage breeding females differed significantly across months (χ2= 27.05, df = 11, p= 0.003) and seasons (χ2= 17.64, p= 0.0003). Breeding females occurred throughout all the months of trapping, but with significantly higher percentages in the months of March to July (i.e. first wet season extending to second dry season) and generally lowest in the first dry months (i.e. January and February in 2017, and February 2018). The results of this study have important consequences for the timing of control efforts, and recommends that control should be initiated during the dry seasons prior to wet seasons to counteract potential damaging population build up in later wet seasons when crop planting is expected.

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 parasites. 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 natalensisto investigate the relationship between exploration, activity, and infection with Morogoro virus (MORV). We characterized individual exploratory behavior (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. natalensisexpresses consistent individual differences, or personality types, in exploratory behavior (repeatability of 0.30, 95% CI: 0.21-0.36). In addition, we found a significant contrasting effect of age on exploration 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.

Differences in the ecological niche requirements among rodent species competing in the same habitat may result from differences in the use of one to three resources: space, time and food or some combination of these. Alternatively, differences in resource use utilization among animal species may simply reflect availability of food, and when food is limited, different animal species compete. In this study, the diet of two rodent pest species, Mastomys natalensisand Gerbilliscus vicinus, coexisting in fallow land in central Tanzania were studied to assess the degree of diet differentiation among them. Dietary niche breadth of G. vicinuswas greater than that of M. natalensisin all stages of the maize cropping seasons. The rodent species studied overlapped considerably in the food items consumed ranging from niche overlap (Ojk) of 0.77–0.89. Grains/seeds featured high in the diet of M. natalensiswhile plant material occurrence was high in G. vicinus.These two food categories may have contributed to differences in diet partitioning, which may, in turn, facilitate their coexistence in fallow land.

As part of a three-year study to develop ecologically-based rodent management (EBRM) in southern Africa, a capture–mark–recapture study was carried out in Tanzania, Namibia and Swaziland to establish the demographic patterns and population dynamics of rodents. Two study grids were established in each country. In Tanzania, ten species of rodents and one shrew (Crocidurasp.) were identified in the study area. The rodent species consisted of Mastomys natalensis, Aethomys chrysophilus, Arvicanthis neumanni, Gerbilliscus vicina, Acomys spinosissimus, Lemniscomys griselda, Lemniscomys zebra, Rattus rattus, Graphiurussp. and Mus minutoides. Mastomys natalensiswas dominant and contributed more than 70% of the captures. In Namibia, five species were captured, namely Mastomys natalensis, Gerbilliscus leucogaster, Saccostomus campestris, Mus minutoidesand Steatomys pratensis. Mastomys natalensiscontributed about 50% of the captures. In Swaziland, only M. natalensiswas captured in the study grids. There was a clear pattern in the population dynamics, with breeding confined to the wet seasons in the three countries. Mastomys natalensiswas the dominant pest species, for which EBRM should focus on. The highest population density of M. natalensisoccurred during and after the rains, which coincided with the most susceptible phenological stage of crops. The breeding seasonality and density fluctuations observed in the three countries conform with observations made elsewhere in Africa, which support the hypothesis that rainfall events promote primary productivity on which murid rodents depend. Development of EBRM in these countries will be determined by the local conditions and how they influence the demographic processes of the rodent populations. EBRM should make use of the available ecological knowledge of the local rodent pest species and the focus should be on (ecological) management practices applicable at the community level including community based intensive trapping, field hygiene, removing cover and sources of food for rodents.

The objective of this multidisciplinary project was to study the intra-specific morphometric and genetic variability between two adjacent populations ofMastomys natalensisSmith, 1834 living in different environments. The study of micro-evolutionary processes at work by using geometrical morphometrics allowed us to define two groups, characterized by different features of the skull shape. Using molecular microsatellites analysis, we showed that the two populations exchanged high gene flow and could be considered as a single panmictic unit. These results suggest that this widely-distributed species exhibits a local population-level differentiation in shape variation of skulls, probably due to different ecological situations. We speculate that the variability in the cranial characteristics (connected with the feeding ability) could reveal a local adaptation preferentially based on the food availability. We propose an explanation linking the shape differences to the fitness gain in the exploitation of resources available in the two environments. Since we suggest a potential differentiation process between populations, we believe that the two groups constitute even better models to understand the factors involved in the early stages of local adaptations.

AbstractThis study investigated mammalian involvement in an outbreak of bubonic plague in Mbulu District, northern Tanzania, in March 2007. Plague is a rodent-borne zoonotic disease that spreads to humans through fleas infected with Yersinia pestis. Live trapping of rodents and shrews was conducted in fallow and crop fields, peri-domestic areas, houses and the neighboring forest reserve. Serum was separated from blood of captured animals. A rapid diagnostic test (RDT) was used for diagnosis of plague infection. An ELISA technique was used to detect antibodies against Yersinia pestisfraction 1 antigen. Wild and commensal rodents tested positive by RDT, indicating current infection in clinically healthy animals. The ELISA showed that wild rodents (Lophuromys flavopunctatus, Praomys delectorum, Graphiurus murinus, Lemniscomys striatus) and commensal rats (Rattus rattus, Mastomys natalensis, Mus minutoides) were Y. pestis-positive. Two potential vectors, Xenopsylla brasiliensisand Dinopsyllus lypusus, were found on wild and commensal rodents with a flea index of 1.8. We conclude that diverse potential mammalian reservoirs and efficient vectors of Y. pestisare present in abundance in Dongobesh and could lead to persistence and future plague outbreaks.

AbstractA total of 750 rodents and shrews were trapped in several sites on Mount (Mt.) Kilimanjaro and in two lowland sites between October 2002 and August 2003. Species diversity variations with altitude and their distribution were established. Diversity of species varied with vegetation type, being highest in the forest and lowest in the lowland areas. The distribution patterns and species diversity of the rodents and shrews were also influenced by habitat complexity and heterogeneity. Species richness was higher in the forest compared to the other areas. The study generally shows that the Mt. Kilimanjaro has high rodent and shrew species diversity and richness.

AbstractWe studied the feeding habits of Mastomys natalensisby analysing a total of 2934 stomachs from individuals snap trapped from maize fields and the surrounding fallow land of central and southwestern Tanzania between February 2001 and October 2002. Mastomys natalensishad a wide range of food items in their diet; however, there was a clear seasonal effect on the consumption of the different food categories. They fed more on seeds, arthropods and grasses during the wet season and on the other plant materials during the dry season. Maize seed was the most preferred diet category, when available. The shifts towards greater consumption of maize, when available, coupled by the high densities attained by this species render it the greatest potential rodent pest in the study areas.

Introduction. Fruit flies (Diptera, Tephritidae) are among the major constraints in commercial horticulture in many African developing countries. Knowledge of the tephritid spectrum in any given area is a prerequisite for the development of an IPM program to alleviate the pest problem. We studied the fruit fly diversity in four main agro-ecological zones which are significant fruit-producing areas in the Morogoro Region, Tanzania. Materials and methods. Fruit fly diversity was investigated for one year (October 2004 ? October 2005). Parapheromones, synthetic food attractant and protein-bait traps were used to trap the flies at the different locations in Morogoro region, Tanzania. One mixed orchard was selected at each of four locations representing the different agro-ecological zones of the region. Results. The recently introduced alien species, Bactrocera invadens, and three indigenous pest species, Ceratitis rosa, Dacus bivittatus and D. punctatifrons, were found at all the four sites, while Bactrocera cucurbitae, Ceratitis cosyra, Dacus chiwira and D. humeralis were found in three out of the four sites. The Sokoine University of Agriculture (SUA) Horticulture Unit and Mikese sites had the highest species diversity while the Mkindo and Nyandira sites had the lowest diversity. The between-habitats diversity (Beta diversity) was similar among the SUA, Mkindo and Mikese sites. Only the Nyandira site had a higher dissimilarity in comparison with the other three sites. Discussion. The most abundant species at low- and mid-elevation sites was Bactrocera invadens while, at high elevation, Ceratitis rosa was the dominant species. Protein-baited traps attracted the highest diversity of fruit flies in comparison with the more specific parapheromones. The synthetic food attractant (three-component lure) was less efficient compared with the protein bait. The large dissimilarity at the Nyandira site is probably due to the different types of host fruits found and grown in high altitude areas (mainly temperate fruits). Fruit fly species associated with these types of fruits, e.g., Ceratitis rubivora and Trirhithrum coffeae, were found only at this site.Introduction. Les mouches des fruits (Diptera, Tephritidae) font partie des principales contraintes de l?horticulture commerciale dans de nombreux pays africains en voie de d?veloppement. La connaissance du spectre des tephritides dans un secteur donn? est un pr?alable au d?veloppement d?un programme d?IPM permettant d?att?nuer le probl?me parasitaire. Nous avons ?tudi? la diversit? des mouches des fruits dans quatre principales zones agro-?cologiques qui sont des zones de production fruiti?re significative dans la r?gion de Morogoro, Tanzanie. Mat?riel et m?thodes. La diversit? des mouches des fruits a ?t? ?tudi?e pendant une ann?e (octobre 2004 ? octobre 2005). Des pi?ges ? paraph?romones, attractifs alimentaires synth?tiques et app?ts prot?in?s ont ?t? utilis?s pour attraper les mouches dans diff?rents endroits de la r?gion de Morogoro. Un verger composite a ?t? choisi pour chacun des quatre lieux repr?sentatifs des diff?rentes zones agro-?cologiques de la r?gion. R?sultats. L?esp?ce ?trang?re Bactrocera invadens, r?cemment introduite, et trois esp?ces nuisibles indig?nes, Ceratitis rosa, Dacus bivittatus et D. punctatifrons, ont ?t? trouv?es aux quatre emplacements prospect?s, alors que Bactrocera cucurbitae, Ceratitis cosyra, Dacus chiwira et D. humeralis ?taient identifi?es dans trois emplacements sur les quatre visit?s. Les sites de l?universit? d?horticulture et d?agriculture de Sokoine (SUA) et de Mikese ont montr? la diversit? d?esp?ces la plus ?lev?e tandis que les localit?s de Mkindo et de Nyandira r?v?laient une plus basse diversit?. La diversit? intra-habitats (b?ta diversit?) a ?t? la m?me pour les sites de SUA, Mkindo et Mikese. Seule la localit? de Nyandira a r?v?l? une dissimilitude plus importante que celle des trois autres localisations. Discussion. L?esp?ce la plus abondante ? basse et moyenne altitudes a ?t? Bactrocera invadens, alors que, ? altitude ?lev?e, Ceratitis rosa a ?t? l?esp?ce dominante. Les pi?ges avec app?t prot?in? ont attir? la plus forte diversit? de mouches des fruits par rapport aux parapheromones plus sp?cifiques. L?attractif alimentaire synth?tique (app?t ? trois composants) a ?t? moins efficace compar? ? l?app?t prot?in?. La grande dissimilitude observ?e ? Nyandira est probablement due aux diff?rents types de fruits h?tes trouv?s et cultiv?s dans ce lieu d?altitude ?lev?e, fruits d?esp?ces temp?r?es principalement. Des esp?ces de mouches des fruits associ?es ? ces types de fruits, Ceratitis rubivora et Trirhithrum coffeae, par exemple, n?ont ?t? trouv?es qu?? cet emplacement.

Introduction. Fruit flies (Diptera, Tephritidae) are among the major constraints in commercial horticulture in many African developing countries. Knowledge of the tephritid spectrum in any given area is a prerequisite for the development of an IPM program to alleviate the pest problem. We studied the fruit fly diversity in four main agro-ecological zones which are significant fruit-producing areas in the Morogoro Region, Tanzania. Materials and methods. Fruit fly diversity was investigated for one year (October 2004 – October 2005). Parapheromones, synthetic food attractant and protein-bait traps were used to trap the flies at the different locations in Morogoro region, Tanzania. One mixed orchard was selected at each of four locations representing the different agro-ecological zones of the region. Results. The recently introduced alien species, Bactrocera invadens, and three indigenous pest species, Ceratitis rosa, Dacus bivittatusand D. punctatifrons,were found at all the four sites, while Bactrocera cucurbitae, Ceratitis cosyra, Dacus chiwiraand D. humeraliswere found in three out of the four sites. The Sokoine University of Agriculture (SUA) Horticulture Unit and Mikese sites had the highest species diversity while the Mkindo and Nyandira sites had the lowest diversity. The between-habitats diversity (Beta diversity) was similar among the SUA, Mkindo and Mikese sites. Only the Nyandira site had a higher dissimilarity in comparison with the other three sites. Discussion. The most abundant species at low- and mid-elevation sites was Bactrocera invadenswhile, at high elevation, Ceratitis rosawas the dominant species. Protein-baited traps attracted the highest diversity of fruit flies in comparison with the more specific parapheromones. The synthetic food attractant (three-component lure) was less efficient compared with the protein bait. The large dissimilarity at the Nyandira site is probably due to the different types of host fruits found and grown in high altitude areas (mainly temperate fruits). Fruit fly species associated with these types of fruits, e.g., Ceratitis rubivoraand Trirhithrum coffeae, were found only at this site.

To study the age structure of two different samples of Mastomys natalensisduring a dry period, we use three different approaches: body weight, tooth wear and eye lens weight. According to each of these techniques, our samples are made up principally of young individuals. Fisher's exact test of significance shows that gender does not appear to be a significant variable between the two samples. These results are consistent with the population cycling of this species and confirm its important dispersion potential. Moreover, in the low rainfall context of winter 2003, our data suggest age differences between the two samples from different habitats. In this study, the variable best correlated with age was eye lens weight for the first age class. The body weight method seems the best adapted to the sampling conditions (small sample size, reproduction period) and its objectives (instantaneous age determination of samples). This study shows that even with limited data sets, some simple precautions during manipulation and a clear understanding of methodological limits provide informative results. If combined with detailed morphological descriptions and molecular variation, these results should give new insights into differentiation processes and models for M. natalensis.

Bactrocera latifrons (Hendel) is a pest of Asian origin, first 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.