Abstract
Urbanisation has caused significant alterations to ecosystems, generally resulting in decreased biodiversity. However, certain animal species persist and thrive in urban environments by making use of available opportunities, anthropogenic resources, infrastructure and increased ambient and surface temperatures. These species are known as urban exploiters. We investigated the southern tree agama, Acanthocercus atricollis population trends, habitat use and basking and shading behaviour in a high-density urban human-populated housing metropolitan area in Pietermaritzburg, KwaZulu-Natal, South Africa. We marked individual southern tree agamas to determine habitat use and territories (n = 37). The southern tree agama population density was high, and they had established set territories here. We conducted monthly observations (February 2017–July 2017 and March 2018–February 2019) to determine the degree of basking and shading behaviour with season and time of day and location. Southern tree agamas invested more than half of their time (57%) in basking behaviour during the overall observational study period. Basking and shading patterns changed with season and time of day. The number of basking southern tree agamas decreased during winter and basking commenced later. We found that increased anthropogenic infrastructure and supplementary food availability, decreased predators, and basking opportunities could have had an influence on their population increase and that the southern tree agama is a potential urban exploiter.
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Acknowledgements
We thank Azalea Gardens Retirement Village for permission to conduct our research. We are most grateful to E. Ally and P. Singh for assistance with banding southern tree agamas. We thank the Ford Wildlife Foundation (ZA) for vehicle support. We are grateful to the University of KwaZulu-Natal (ZA), the National Research Foundation (ZA) and the Deutscher Akademischer Austauschdienst/ German Academic Exchange Service (DAAD) for funding.
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Data will be available on request and is lodged at the University of KwaZulu-Natal.
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The present research was funded by the National Research Foundation (ZA) and Deutscher Akademischer Austauschdienst/ The German Academic Exchange Service (DAAD).
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NS conceived paper with CTD and CP. CTD sourced funding. NS collected and analysed data and wrote the manuscript. CP assisted with data collection. CTD and CP both assisted with methodology, providing valuable literature, references and editing and proofing of the text.
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Ethical clearance was obtained from the University of KwaZulu-Natal Animal Ethics Committee (Permit no. AREC/032/018 M) in order to capture and mark southern tree agamas.
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Singh, N., Price, C. & Downs, C.T. Aspects of the ecology and behaviour of a potential urban exploiter, the southern tree agama, Acanthocercus atricollis. Urban Ecosyst 24, 905–914 (2021). https://doi.org/10.1007/s11252-020-01078-z
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DOI: https://doi.org/10.1007/s11252-020-01078-z