E-Thesis 439 views 239 downloads
Investigating the potential impact on native flora and fauna of a non-native macropod, the red-necked wallaby (Notamacropus rufogriseus), on the Isle of Man / KAI DAVIES
Swansea University Author: KAI DAVIES
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PDF | E-Thesis
Copyright: The author, Kai Davies, 2024 Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0)
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Abstract
AbstractIntroduced non-native mammals to island ecosystems can cause significant impact on native flora and fauna. Large herbivores present in high density can cause significant changes in woodland vegetation dynamics and composition, altering biodiversity considerably. Since their escape from a zoo...
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Swansea University, Wales, UK
2025
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| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MRes |
| Supervisor: | Borger, L., and Devine, A. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa69774 |
| Abstract: |
AbstractIntroduced non-native mammals to island ecosystems can cause significant impact on native flora and fauna. Large herbivores present in high density can cause significant changes in woodland vegetation dynamics and composition, altering biodiversity considerably. Since their escape from a zoo in the mid-20th century, the red-necked wallaby (Notamacropus rufogriseus) has established multiple dense populations in the north of the Isle of Man, now exceeding 500 individuals. The wallabies are frequently reported to be in poor physical condition, and so investigations into the potential causes of their symptoms are of importance to stakeholders in the animal agriculture industry whose animals share habitat with the wallabies, as well as animal welfare groups. With the majority of wallabies inhabiting the northwest curraghyn, a RAMSAR and ASSI site, there is great concern for the impact they may be having on native species. However, there have not been any quantifiable studies assessing the impact of wallaby presence on vegetation composition on the island. Here we show that the wallabies are causing significant reductions in vegetation height and cover but not in biomass. We found that vegetation cover was significantly reduced in grasses and other non-woody vegetation, but was not significantly reduced in ferns, mosses nor rushes.There were indications from rapid assessments undertaken, that browsing damage is occurring due to bark stripping by the wallabies, whilst they cause minimal impact to woodland via mechanic disturbance and stem consumption. We found that it is unlikely that the reported health issues commonly seen in the wallaby population are caused by parasitic helminth infection, although their parasitic load and feeding behaviour suggest they may increase spread of disease across the region. Our results demonstrate how the wallabies of the Isle of Man are significantly altering the vegetation composition of their habitat and so potentially shifting the species evenness of the region. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
Wallaby, herbivore, Woodland conservation, Isle of Man, non-native species, impact assessment |
| College: |
Faculty of Science and Engineering |