Molecular screening of potential bat-borne hantavirus and determination of species richness and composition of bats in selected habitats within the woodland and savanna biomes in Namibia
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Date
2020
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University of Namibia
Abstract
Bats are present and they play unique ecological roles in various habitats in Namibia. Yet the patterns of species richness and composition of bats associated with these habitats within different biomes in Namibia still remain unknown. Bats are also important carrier hosts and transmitters of zoonotic viruses of public health significance including old and emerging hantaviruses. The burden of hantavirus disease is globally well-documented but this remains unknown and unrecognised in many African countries including in Namibia. This study investigated the patterns of species richness and composition of bats as well as the potential prevalence of bat-borne hantaviruses at selected habitats in the broad-leaved tree and shrub savanna, and the Acacia tree and shrub savanna biomes in Namibia. Live bats were sampled using Dinier mist nets, biometrically processed and the species identifications were morphologically and molecularly determined. Blood and organ tissue samples were collected from live and sacrificed bats respectively, and they were molecularly screened for hantavirus using the two-step Pan-Hanta RT- PCR technique. A total of 219 bat captures were recorded from 17 selected habitats in both the broad-leaved tree (n = 7) and Acacia tree (n = 10) savanna biomes. Only 103 bat lung and blood samples were collected and screened for hantavirus. No hantavirus however was detected. A combined total of 11 species of bats were recorded from selected habitats in both biomes, and these included the following four families of the order Chiroptera: 1) Pteropodidae (1 species); 2) Molossidae (3 species); 3) Vespertilionidae (5 species); and 4) Rhinolophidae (2 species). Seven bat species were observed in selected habitats in the broad-leaved and eight in the Acacia tree savanna biomes, while 9 and 12 species,
respectively, were predicted. Species richness of bats did not differ significantly across the biomes. In addition, there was no significant difference in species composition between selected habitats in the two biomes. Thus the influence of the biomes on the species richness and composition of bats appears to be minimal at a broad spatial scale. The results indicate a compositional overlap in species of bats in selected habitats across biomes which suggest that the two biomes broadly harbour similar species. Habitats characterised by riparian vegetation, non-perennial riverine vegetation, and semi-urban environments were up to four times more species rich than other habitats. These habitats may represent important areas that support high species richness of bats characterised by variable patterns of species composition, based on species habitat requirements. In addition, four highway bridges at selected habitats in the Acacia tree and shrub savanna biomes showed high abundance of Robert’s flat-headed bat (Sauromys petrophilus), indicating the importance of bridges to the roosting ecology and hence conservation of the species. Since no hantavirus could be detected, future detection of hantavirus and to gain more insights into our understanding of in situ patterns of bat species richness and composition may require more intensive sampling efforts and screening of bats in various habitats, and using a range of active (e.g., mist nets and harp traps) and passive (e.g., acoustic recording devices such as an Anabat) efforts.
Description
A thesis submitted in fulfillment of the requirements for the Degree of Master of Science in Biology
Keywords
Bat-borne hantaviruses, Species richness and composition, Molecular techniques, Cytochrome b