Microhabitat choice and diet of rodents in Maynugus irrigation field, northern Ethiopia

Land Preservation Uptakes in the Escarpments of North-Eastern Ethiopia: Drivers, Sustainability, and Constraints

Agricultural land is an indispensable resource for agrarian communities worldwide. There is a growing awareness that the world’s arable land supplies are limited and finite. For the last five decades, the Government of Ethiopia (GoE) and other development organisations have carried out land preservation uptakes intended to curb the effects of land degradation and improve agricultural productivity through various soil and water conservation practices (SWCPs). The study assessed the sustainability, drivers, and constraints of SWCPs in Dessie Zuria and Kutaber Woredas of South Wollo. We used the exploratory case study approach, involving qualitative and quantitative methods. Catastrophic weather conditions, the presence of the soil and water conservation program, and declining soil fertility were the top drivers influencing the program’s implementation. Based on the identified farm-level indicators and views of the respondents, physical measures were more sustainable than biological and mixed methods. The prominent factors hurdling the intervention were lack of tenure security, risk of rodent infestation, and losing a sense of ownership. Training community members on the importance of land preservation, amending the existing rigid land tenure policy, incorporating indigenous SWCPs, broadening the scale and extent of community participation, and enforcing laws and bylaws are recommended for the upcoming interventions. The finding has implications for land preservation and food security actors working to scale up evidence-based sustainable land management practices to the broader area.

Distribution, diet, and trophic level of Arvicanthis abyssinicus and Tachyoryctes splendens around the area of recently extinct Ethiopian Wolf Canis simiensis on Mount Guna, northwestern Ethiopia

Abyssinian Grass Rats Arvicanthis abyssinicus and Common Mole Rats Tachyoryctes splendens are preyed upon by the Ethiopian Wolf Canis simiensis. The aim of this study was to assess distribution, diet and trophic level of Arvicanthis abyssinicus and Tachyoryctes splendens on Mount Guna, where wolves have recently become extinct. Rodents were captured with Sherman trap and identified, and samples were taken to Debre Tabor University for dissection and diet analysis via microscopy examination of stomach contents. 110 A. abyssinicus and 52 T. splendens were captured from the study area, and the estimated population sizes of A. abyssinicus and T. splendens in Mt. Guna computed by Peterson-Lincoln Index were 1,364 and 416, respectively. In addition, 379 burrows (203 of A. abyssinicus and 176 of T. splendens) were counted. Both species were observed to consume plants and arthropods, with plants predominant. We recommend that intensive studies should be carried out to determine the effects of rodent communities upon Mt. Guna afroalpine and subafroalpine ecosystems.

Assessment of crop damage by rodent pests from experimental barley crop fields in Farta District, South Gondar, Ethiopia

This study was conducted in Farta district, south Gondar from 2019 to 2020 cropping years to identify rodent pest species and estimate damage caused on barley crops. Four independent barley crop fields (40 x 40 m each) were sampled randomly to estimate the loss. Two were located near Alemsaga Priority State Forest and the other two were away from the forest. Four (2 x 2 m) rodent exclusion plots were established at 10 m interval as control units in each selected experimental barley fields using fine wire mesh. Rodent pest species were collected using both Sherman and snap traps throughout the different crop growing stages. The damaged and undamaged barley tillers by pest rodents were counted on five 1 x 1 m randomly sampled quadrats for each selected experimental fields. Variations on pest rodent population between cropping years and sites were analyzed using Chi square test. The mean crop damages between cropping years and experimental field sites were analyzed using two way ANOVA. Arvicanthis abyssinicus, Mastomys natalensis, Arvicanthis dembeensis, Mus musculus, Lophuromys simensis, Tachyoryctes splendens and Hystrix cristata were identified as pest rodents in the study area. A total of 968 individual rodents (427 in 2019 and 541 in 2020) were trapped during the study period. There was a statistical variation (χ² = 13.42, df = 1 and P<0.05) between trapped individuals of the two successive years. The crop fields near the forest were more vulnerable than away from the forest during both cropping years. Statistical variations was observed on mean crop losses between cropping years and experimental barley crop sites. The highest crop damage was seen at maturity stage and the lowest during sowing in all experimental plots and cropping years. The percentage of barley yield loss due to rodent pests was 21.7 kg ha^-1. The monetary value of this yield loss was equivalent to 4875 Birr (121.9 US$ h^-1). Alemsaga Forest as shelter and conservation strategies like free of farmland from livestock and terracing for soil conservation have great role for the high rodent pest populations in the study area. Field sanitation, trapping and using restricted rodenticides like zinc phosphide are the possible recommendation to local farmers against rodent pests.

Season and habitat affect diversity, abundance and reproductive state of small mammals near Lake Abaya, Ethiopia

This study investigated the spatio-temporal association of small mammals in human-modified habitats. Small mammals were sampled using Sherman traps along 200 m transects (with one trap at every 10 m interval) in each of four habitats (cropland, forest patch, scrubland and wetland) replicated twice. Additional trapping was carried out in rural settlements comprising of eight homesteads, with five traps per homestead. Trapping was conducted in three sessions during the agricultural seasons: rainy (October), off-rain (December) and dry (February) over two years (2018 and 2019). In each session, trapping was carried out for three consecutive nights. A total of 497 small mammals belonging to 12 species from four families (Soricidae, Macroscelididae, Gliridae and Muridae) were captured. Murine rodents accounted for 99.4% of the animals with Mastomys erythroleucus (58%) being the dominant species. The scrubland had the highest small mammal species diversity while the cropland had the lowest. M. erythroleucus was not strongly associated with any spatio-temporal parameter and scored majority of seasonally reproducing individuals in the cropland, signifying its pest importance. Though disconnected from protected areas, habitats such as the scrubland harbor diverse small mammal species (including a vulnerable-endemic species, Grammomys minnae), suggesting the habitats’ significance for ecosystem functioning and conservation.

Reproduction and survival of rodents in crop fields: the effects of rainfall, crop stage and stone-bund density

Context Reproduction and survival are two of the most important demographic factors that play a major role in changing population abundances of pest species over time and space, solid understanding of which is a useful input to forecast future population changes for proactive management. Aims We investigated the effects of rainfall, crop-development stage and density of stone bunds on reproductive patterns, and the effects of stone-bund density and sex on survival probabilities of two widespread rodent species (Mastomys awashensis and Arvicanthis dembeensis) in Ethiopian highlands. Methods Rodent population dynamics were monitored from April 2007 to February 2011, using capture–mark–recapture (CMR) technique in four 60 × 60 m permanent square grids for four consecutive cropping seasons. Two of the grids represented fields with low stone-bund density (LSBD, ~15 m apart) and the other two represented fields with high stone-bund density (HSBD, ~10 m apart). Key results Reproduction was seasonal, commencing during the wet season following the rain and continuing through the early dry season. We found an increase in the abundance of reproductively active female individuals of both species towards the milky and fruiting crop stages and around harvest period. We found no strong difference in survival probability between the two rodent species with variation in stone-bund density and sex. Conclusion Stone bunds play a minor role in the reproduction and survival of the rodent species at the observed abundances. Implications In terms of pest management, the high local survival rates estimated for both rodent species matter more than survival differences owing to variations in stone-bund density and sex.

Seasonal and habitat dependence of fleas parasitic on small mammals in Tanzania

We investigated host and flea species composition across different habitats during dry and rainy seasons in the Western Usambara Mountains in Tanzania. During both seasons, similarity in flea species composition increased with an increase in the similarity in host species composition. Nevertheless, between-season within-habitat as well as within-season between-habitat similarity in host species composition was higher than similarity in flea species composition. Ordination of habitats according to their host and flea species composition demonstrated that the pattern of between-habitat similarity in both host and flea species composition varied seasonally. Despite the relatively rich mammal and flea fauna of the study region, the major contribution to variation in species composition between seasons and among habitats was due to a few species only. Flea assemblages on Lophuromys kilonzoi Verheyen et al., 2007 and Praomys delectorum Thomas, 1910 in different habitats were equally similar in either season. In contrast, flea assemblages on Mastomys natalensis (Smith, 1834) occurring in different habitats were more similar in the dry than in the rainy season, whereas the opposite was the case for fleas on Grammomys sp. In different hosts, the main differences in species composition of flea assemblages between seasons as well as among habitats were due to different flea species. Although our results support the earlier idea that parasite species composition is determined by both host species composition and habitat properties, the former appears to explain variance in flea species composition between localities in the tropics better than between localities in temperate and arid zones.