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Temporal changes in food resource availability between two karst bat assemblages

Dissertation (MSc (Wildlife Management))--University of Pretoria, 2020.

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Other Authors: Keith, Mark
Format: Thesis
Language:English
Published: University of Pretoria 2024
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access_status_str Open Access
author2 Keith, Mark
author_browse Keith, Mark
author_facet Keith, Mark
collection Thesis
dc_rights_str_mv © 2021 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MSc (Wildlife Management))--University of Pretoria, 2020.
format Thesis
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:39:51.634Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2024
publishDateRange 2024
publishDateSort 2024
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/98026 Temporal changes in food resource availability between two karst bat assemblages Keith, Mark tlaishegonkoana@gmail.com Seamark, Ernest Nkoana, Tlaishego Tedson UCTD Food resource availability Karst bat assemblages Temporal changes Dissertation (MSc (Wildlife Management))--University of Pretoria, 2020. The temporal availability of arthropods varies in response to changing quality of vegetation which is influenced by climatic conditions. Climate in the Savanna and Grassland biomes is defined by wet and dry cycles. Bats (Chiroptera) are major consumers of nocturnal flying arthropods and respond to temporal fluctuations of their arthropod prey as well as climatic conditions. My study is undertaken in two karst landscapes within two biomes, Savanna (Meletse) and Grassland (Cradle of Humankind World Heritage Site-CoH WHS). The migratory Miniopterus natalensis utilizes Madimatle cave (Meletse –Thabazimbi) for maternity roosting (October-February/March) whilst caves in the CoH WHS provide hibernacula (winter) roosts (April-September) for this population. Migration in bats has been linked to changing climatic conditions for temperate species and food availability in tropical species. The factors driving the migration of Min. natalensis population are not yet understood. The temporal changes of bat assemblages and their arthropod prey from dry to wet season climatic regimes are of interest. To test this, I collected arthropods and recorded bat echolocation calls from dry to wet season (June-February), using malaise traps and Anabat SD2 bat detectors, respectively. Different bat species are adapted to forage within different levels of vegetation clutter. Traps and bat detectors were therefore spatially placed across different levels of vegetation clutter at the study sites. Arthropods were caught, measured (size and biomass) and capture success (CS=individuals/trap-hours) were calculated monthly. An Acoustic Activity Index (AAI) of recorded bats was also used to obtain monthly relative activity. My results show that bat activity corresponds to arthropod availability on a temporal basis with wet season highs and dry season lows, at both study sites. When comparing Grassland and Savanna sites, arthropod CS was significantly higher (P<0.01) at the grassland (mean CS=0.248 ind./trap) whilst biomass was greater at the savanna site. In addition, the Grassland had higher CS with lower biomass for the arthropods Diptera and Lepidoptera, whilst the larger biomass taxa, Coleoptera and Hemiptera, had higher CS at the savanna. The frequency of larger arthropods was higher in November and corresponded with peak biomass measured that month. At Meletse, significant increases (P<0.05) for bat activity and arthropod CS were recorded in August/September (late dry season) and November (wet season). Species level bat activity increases corresponded with increases in arthropod CS and biomass. The matching between bat activity patterns and arthropod availability is important for the maternity season when pregnant females have to meet increased energy demands. Indeed, the maternity season matched with periods of highest food resources expressed as increased arthropod abundance and biomass. Greater bat activity during the maternity period places Meletse as an important food resource reservoir both supporting resident and the migratory species. As bats are major predators of several taxa of nocturnal flying arthropods amongst which are agricultural pests, the ecological and economic implications of maintaining healthy bat assemblages remain of importance. Careful and effective monitoring of bat assemblages and arthropod prey will further increase understanding of the temporal dynamics between predator activity and prey abundance within habitats. Knowledge on the effects of land-use change on habitats will develop a better understanding of impacts on species and broader ecological systems. Zoology and Entomology MSc (Wildlife Management) Unrestricted Faculty of Natural and Agricultural Sciences 2024-09-05T06:38:41Z 2024-09-05T06:38:41Z 2020-04 2020 Dissertation * A2020 http://hdl.handle.net/2263/98026 en © 2021 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Food resource availability
Karst bat assemblages
Temporal changes
Temporal changes in food resource availability between two karst bat assemblages
title Temporal changes in food resource availability between two karst bat assemblages
title_full Temporal changes in food resource availability between two karst bat assemblages
title_fullStr Temporal changes in food resource availability between two karst bat assemblages
title_full_unstemmed Temporal changes in food resource availability between two karst bat assemblages
title_short Temporal changes in food resource availability between two karst bat assemblages
title_sort temporal changes in food resource availability between two karst bat assemblages
topic UCTD
Food resource availability
Karst bat assemblages
Temporal changes
url http://hdl.handle.net/2263/98026