Browsing by Author "Isabirye, Moses"

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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
Pre-harvest Loss Assessment of Maize crop in Semi-arid Areas in Tanzania Due to Rodent pests
(African Journal of Agricultural Research, 2022) Mlyashimbi, Emmanuel C. M.; Kimaro, Didas N.; Tarimo, Akwilin J. P.; Machang’u, Robert S.; Isabirye, Moses; Makundi, Rhodes H; Leirs, Herwig; Massawe,Apia W.; Mdangi, Mashaka E.; Belmain, Steven R.; Mulungu, Loth S.
Two experiments were conducted, first was to estimate maize seedling damage in farmers’ fields and a simulation experiment. This study aim to investigate the impact of rodent pest species, damage to maize crop in semi-arid areas at pre-harvest, with a view to provide farmers with appropriate information on rodent pest management interventions. In farmers’ fields, damage assessment was done by counting the number of damaged or removed seedlings at each planting hole while yield loss was determined from simulation experiment at five damage levels, viz; 0, 10, 25, 50, and 75% by removing seedlings per plot. Variation of damaged maize seedlings was compared between soil type and fields. The fields with black clay soils had higher damage of maize seedling (mean = 59.201±1.714) as compared to sandy loam soils (means = 49.742±1.714). The damage ranged from 30.17 to 71.91% in different fields. However, no effect was observed between interactions of maize fields and soil types. Results from simulation experiment showed no significant difference (p = 0.2357) among maize damage levels, although relatively higher yield losses were observed at 75%, while lowest yield losses in the control (0%). The increased seedling damage has an impact on final harvest; therefore, ecologically- based rodent management strategies appear to be good solution for reducing crop damage and should be encouraged to improve food security for smallholder farmers.
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).
Species composition and community structure of small pest rodents (Muridae) in cultivated and fallow fields in maize‐growing areas in Mayuge district, Eastern Uganda
(Wiley, 2019) Mayamba, Alex; Byamungu, Robert M.; Makundi, Rhodes H.; Kimaro, Didas N.; Isabirye, Moses; Massawe, Apia W.; Kifumba, David; Nakiyemba, Alice; Leirs, Herwig; Mdangi, Mshaka E.; Isabirye, Brian E.; Mulungu, Loth S.
1. Pest rodents remain key biotic constraints to cereal crops production in the East African region where they occur, especially in seasons of outbreaks. Despite that, Uganda has scant information on rodents as crop pests to guide effective management strategies. 2. A capture–mark–recapture (CMR) technique was employed to study the ecology of small rodents, specifically to establish the species composition and community structure in a maize‐based agro ecosystem. Trapping of small rodents was conducted in permanent fallow land and cultivated fields, with each category replicated twice making four study grids. At each field, a 60 × 60 m grid was measured and marked with permanent trapping points spaced at 10 × 10 m, making a total of 49 trapping points/grids. Trapping was conducted monthly at 4‐week interval for three consecutive days for two and half years using Sherman live traps. 3. Eleven identified small rodent species and one insectivorous small mammal were recorded with Mastomys natalensis being the most dominant species (over 60.7%). Other species were 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%). Spatially, species richness differed significantly (p = 0.0001) between the studied field habitats with significantly higher richness in fallow land compared with cultivated fields. 4. Temporally, total species richness and abundance showed a significant interaction effect over the months, years, and fields of trapping with significantly (p = 0.001) higher abundances during months of wet seasons and in the first and third year 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. 5. Synthesis and applications. Based on these findings, management strategies can be designed to target the key pest species and the most vulnerable habitats thus reducing the impact they can inflict on field crops.