Diversity and temporal fluctuations in abundance of rodents, shrews and their flea- ectoparasites in an extensive agricultural landscape of Mgeta division, Morogoro region, Tanzania

Loading...
Thumbnail Image

Date

2024-05

Journal Title

Journal ISSN

Volume Title

Publisher

Sokoine University of Agriculture

Abstract

Rodents and shrews play an important role in a variety of ecosystems including crop farming and the keeping of food animals. Increasing cultivation of crops and livestock keeping in Mgeta division, along the western slopes of Uluguru Mountain, is threatening the survival of rodents and shrews, and consequently, changes in the likelihood of these animals in their disease transmission patterns, which involves also their ectoparasites, particularly fleas, due to changes in their abundance and distribution in the ecosystem. This study was conducted from December 2021 to May 2022, and intended to investigate the diversity and temporal fluctuations in abundance of rodents, shrews and their flea- ectoparasites in Mgeta, an area with extensive agriculture in south- east Tanzania. Three habitats (forest, fallow and cultivated lands), each, were selected and defined as low (1,100 - 1,500 m a.s.l) and high (1,600 - 1,900 m a.s.l) elevations and subsequently sampled for rodents, shrews and their flea-ectoparasites. Removal trapping with baited live Sherman®, Harvahart® and locally made traps was carried out. A total of 192 rodents and 15 shrews were captured, and 199 fleas were collected. Identification of the rodents, shrews and fleas was done up to their species levels. Captured rodents included: Rattus rattus (1.45%), Mastomys natalensis (9.66%), Beamys hindei (1.45%), Lophuromys flavopunctatus (21.74%), Lophuromys kilonzoi (2.42%), Praomys delectorum (40.58%), Grammomys ibeanus (8.7%), Graphiurus murinus (1.45%), Mus minutoides (3.38%), Mus musculus (1.45%) and Dasmys spp (0.48%), whereas, the shrew species included: Crocidura olivieri (3.86%) and Crocidura hirta (3.38%). A Total number of 95 (45.89%) rodents and 6 (2.8%) shrews were infested by Dinopsyllus lypusus, Nosopsyllus fasciatus or Ctenopthalmus calceatus. The mean abundance of fleas presented a significant variation among the host species (F (12, 194) = 11.82, P < 0.001), habitats (F (2, 204) = 9.935, P < 0.001) and along the elevation gradient (F (1, 205) = 10.15, P = 0.02). Similarly, the prevalence varied significantly between the hosts (F (12, 194) = 22.44, P < 0.001) and habitats (F (2, 204) = 4.837, P = 0.009) but not with elevation (F (1, 205) = 0.291, P = 0.59). The mean intensity of flea infestation, on the other hand, varied significantly among the hosts (F (12, 194) = 9.257, P < 0.001) and along the elevation gradient (F (1, 205) = 47.91, P < 0.001), but not habitats (F (2, 204) = 0.75, P = 0.474). Furthermore, while rainfall intensity was strongly associated with mean abundance of fleas (r = 0.054, P < 0.05), neither temperature, elevation, nor humidity were correlated with either mean intensity or prevalence of fleas on the hosts. However, rainfall, temperature, and relative humidity had a significant effect on rodent and shrew abundance (P< 0.05). Given the discovery of D. lypusus, which is a well-known vector of the plague pathogen, Yersinia pestis, and a common ectoparasite of M. natalensis and R. rattus. Effective conservation strategies to preserve the remainder forest patches and community awareness programs regarding the existence of potential plague vectors and mitigation measures in the study area as well as avoidance mechanism should be implemented to ensure the health of the entire ecosystem.

Description

MSc. Public Health Pest Management

Keywords

Rodents, Shrews, Their Flea- Ectoparasites, Extensive Agricultural Landscape, Mgeta Division, Morogoro Region, Tanzania

Citation