Investigating the effects of management practice on mammalian co-occurrence along the West Coast of South Africa
The subtle and cascading effects (e.g., altered interspecific interactions) that anthropogenic stressors have on local ecological assemblages often go unnoticed but are concerning given their importance in ecosystem function. For example, elimination of buffalo from the Serengeti National Park is su...
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| Format: | Article |
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PeerJ Inc.
2020-01-01
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| Series: | PeerJ |
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| Online Access: | https://peerj.com/articles/8184.pdf |
| _version_ | 1797424187352023040 |
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| author | Deborah Jean Winterton Nicola J. van Wilgen Jan A. Venter |
| author_facet | Deborah Jean Winterton Nicola J. van Wilgen Jan A. Venter |
| author_sort | Deborah Jean Winterton |
| collection | DOAJ |
| description | The subtle and cascading effects (e.g., altered interspecific interactions) that anthropogenic stressors have on local ecological assemblages often go unnoticed but are concerning given their importance in ecosystem function. For example, elimination of buffalo from the Serengeti National Park is suggested to have driven increased abundance of smaller antelope as a result of release from competition. The perceived low abundance of small antelope in the contractual Postberg section of the West Coast National Park (the park) has been an ongoing management concern which has been anecdotally attributed to predation by a mesopredator (the caracal, Caracal caracal). However, we hypothesized that the historical overstocking, and consequent overgrazing by larger-bodied managed ungulates would influence small antelope abundance. Using camera traps, we investigated species co-occurrence and temporal activity between small antelope, managed ungulates and caracals in Postberg as well as another part of the park (Langebaan) and a farm outside of the park. Results suggest that small antelope and managed ungulates have a high degree of temporal overlap (Δ = 0.74, 0.79 and 0.86 for the farm, Langebaan and Postberg respectively), while temporal partitioning between small antelope and caracal is apparent (Δ = 0.59). Further, small antelope and managed ungulates appear to occur independently of one another (SIF = 0.91–1 across areas). Managed ungulates were detected almost three times more frequently on fallow lands when compared to the more vegetated sites within the park suggesting that segregated food/cover resources allow for independent occurrence. Small antelope had a much higher probability of occurrence outside of the protected area (e.g., ψ = 0.192 and 0.486 for steenbok at Postberg, Langebaan compared to 0.841 on the farm), likely due to less variable (more intact) habitat outside of the protected area. There is not sufficient evidence to currently warrant management intervention for predators. The small size of the protected area provides limited scope for spatial replication thus reducing possibilities to infer the cause and effect for complex interactions (which would historically have taken place over much larger areas) with negative implications for adaptive management. We recommend continued monitoring over multiple seasons and a wider area to determine the spatial information requirements to inform management of small protected areas. |
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| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T07:58:38Z |
| publishDate | 2020-01-01 |
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| spelling | doaj.art-77dfa0b764b8466b9c69ce5df59bb79d2023-12-03T00:50:08ZengPeerJ Inc.PeerJ2167-83592020-01-018e818410.7717/peerj.8184Investigating the effects of management practice on mammalian co-occurrence along the West Coast of South AfricaDeborah Jean Winterton0Nicola J. van Wilgen1Jan A. Venter2Cape Research Centre, SANParks Scientific Services, Cape Town, South AfricaCape Research Centre, SANParks Scientific Services, Cape Town, South AfricaSchool of Natural Resource Management, Faculty of Science, Nelson Mandela University, George, South AfricaThe subtle and cascading effects (e.g., altered interspecific interactions) that anthropogenic stressors have on local ecological assemblages often go unnoticed but are concerning given their importance in ecosystem function. For example, elimination of buffalo from the Serengeti National Park is suggested to have driven increased abundance of smaller antelope as a result of release from competition. The perceived low abundance of small antelope in the contractual Postberg section of the West Coast National Park (the park) has been an ongoing management concern which has been anecdotally attributed to predation by a mesopredator (the caracal, Caracal caracal). However, we hypothesized that the historical overstocking, and consequent overgrazing by larger-bodied managed ungulates would influence small antelope abundance. Using camera traps, we investigated species co-occurrence and temporal activity between small antelope, managed ungulates and caracals in Postberg as well as another part of the park (Langebaan) and a farm outside of the park. Results suggest that small antelope and managed ungulates have a high degree of temporal overlap (Δ = 0.74, 0.79 and 0.86 for the farm, Langebaan and Postberg respectively), while temporal partitioning between small antelope and caracal is apparent (Δ = 0.59). Further, small antelope and managed ungulates appear to occur independently of one another (SIF = 0.91–1 across areas). Managed ungulates were detected almost three times more frequently on fallow lands when compared to the more vegetated sites within the park suggesting that segregated food/cover resources allow for independent occurrence. Small antelope had a much higher probability of occurrence outside of the protected area (e.g., ψ = 0.192 and 0.486 for steenbok at Postberg, Langebaan compared to 0.841 on the farm), likely due to less variable (more intact) habitat outside of the protected area. There is not sufficient evidence to currently warrant management intervention for predators. The small size of the protected area provides limited scope for spatial replication thus reducing possibilities to infer the cause and effect for complex interactions (which would historically have taken place over much larger areas) with negative implications for adaptive management. We recommend continued monitoring over multiple seasons and a wider area to determine the spatial information requirements to inform management of small protected areas.https://peerj.com/articles/8184.pdfVegetation structureSteenbokCommon duikerCaracalOver-stockingUngulates |
| spellingShingle | Deborah Jean Winterton Nicola J. van Wilgen Jan A. Venter Investigating the effects of management practice on mammalian co-occurrence along the West Coast of South Africa PeerJ Vegetation structure Steenbok Common duiker Caracal Over-stocking Ungulates |
| title | Investigating the effects of management practice on mammalian co-occurrence along the West Coast of South Africa |
| title_full | Investigating the effects of management practice on mammalian co-occurrence along the West Coast of South Africa |
| title_fullStr | Investigating the effects of management practice on mammalian co-occurrence along the West Coast of South Africa |
| title_full_unstemmed | Investigating the effects of management practice on mammalian co-occurrence along the West Coast of South Africa |
| title_short | Investigating the effects of management practice on mammalian co-occurrence along the West Coast of South Africa |
| title_sort | investigating the effects of management practice on mammalian co occurrence along the west coast of south africa |
| topic | Vegetation structure Steenbok Common duiker Caracal Over-stocking Ungulates |
| url | https://peerj.com/articles/8184.pdf |
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