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How well do buffer circles capture the ranging behaviours of territorial raptors?
As the world's human population increases, so does the competition for natural resources between humans and wildlife. This competition may be intense for apex predators, such as raptors, which generally require large natural areas in order to maintain their populations. Anthropogenic development wit...
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| Format: | Thesis |
| Language: | English |
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FitzPatrick Institute of African Ornithology
2021
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| _version_ | 1867613777784995840 |
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| access_status_str | Open Access |
| author | Brink, René |
| author2 | Amar, Arjun |
| author_browse | Amar, Arjun Brink, René |
| author_facet | Amar, Arjun Brink, René |
| author_sort | Brink, René |
| collection | Thesis |
| description | As the world's human population increases, so does the competition for natural resources between humans and wildlife. This competition may be intense for apex predators, such as raptors, which generally require large natural areas in order to maintain their populations. Anthropogenic development within territories can cause individuals to either abandon these sites, reduce their breeding productivity, or cause direct mortality to the territory holding birds. To mitigate such impacts, one method, employed as part of Environmental Impact Assessments (EIA), is the use buffer circles centred on nest sites. Within these buffers the most damaging forms of development are prohibited. This approach assumes that raptors use the space around their nest in a uniform way, but this assumption may not always be correct and few have evaluated the effectiveness of buffer circles at protecting a species' home range. This study uses tracking data to evaluate the effectiveness of buffer circles to cover the ranging movements of six southern African raptor species, throughout the year, as well as during their breeding and non-breeding season. My study revealed that buffer circles whose dimensions were based on the species' 95% Kernel Density Estimate (KDE) did relatively well at capturing the proportion of individual GPS fixes, but did less well at capturing the KDE area from tracked birds. For buffer circles to capture 95% of the home range polygons (95% KDE) they would generally need to be at least twice as large as those that were derived from the 95% KDE home range area, and for some species with very large home ranges (e.g. Lappet-faced Vultures) even buffer circles that were 3 times the size failed to cover 95% of the KDE polygons. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/33229 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:41:32.839Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2021 |
| publishDateRange | 2021 |
| publishDateSort | 2021 |
| publisher | FitzPatrick Institute of African Ornithology |
| publisherStr | FitzPatrick Institute of African Ornithology |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/33229 How well do buffer circles capture the ranging behaviours of territorial raptors? Brink, René Amar, Arjun Murgatroyd, Megan Conservation Biology As the world's human population increases, so does the competition for natural resources between humans and wildlife. This competition may be intense for apex predators, such as raptors, which generally require large natural areas in order to maintain their populations. Anthropogenic development within territories can cause individuals to either abandon these sites, reduce their breeding productivity, or cause direct mortality to the territory holding birds. To mitigate such impacts, one method, employed as part of Environmental Impact Assessments (EIA), is the use buffer circles centred on nest sites. Within these buffers the most damaging forms of development are prohibited. This approach assumes that raptors use the space around their nest in a uniform way, but this assumption may not always be correct and few have evaluated the effectiveness of buffer circles at protecting a species' home range. This study uses tracking data to evaluate the effectiveness of buffer circles to cover the ranging movements of six southern African raptor species, throughout the year, as well as during their breeding and non-breeding season. My study revealed that buffer circles whose dimensions were based on the species' 95% Kernel Density Estimate (KDE) did relatively well at capturing the proportion of individual GPS fixes, but did less well at capturing the KDE area from tracked birds. For buffer circles to capture 95% of the home range polygons (95% KDE) they would generally need to be at least twice as large as those that were derived from the 95% KDE home range area, and for some species with very large home ranges (e.g. Lappet-faced Vultures) even buffer circles that were 3 times the size failed to cover 95% of the KDE polygons. 2021-05-05T14:01:27Z 2021-05-05T14:01:27Z 2020 2021-05-05T14:00:48Z Master Thesis Masters MSc http://hdl.handle.net/11427/33229 eng application/pdf FitzPatrick Institute of African Ornithology Faculty of Science |
| spellingShingle | Conservation Biology Brink, René How well do buffer circles capture the ranging behaviours of territorial raptors? |
| thesis_degree_str | Master's |
| title | How well do buffer circles capture the ranging behaviours of territorial raptors? |
| title_full | How well do buffer circles capture the ranging behaviours of territorial raptors? |
| title_fullStr | How well do buffer circles capture the ranging behaviours of territorial raptors? |
| title_full_unstemmed | How well do buffer circles capture the ranging behaviours of territorial raptors? |
| title_short | How well do buffer circles capture the ranging behaviours of territorial raptors? |
| title_sort | how well do buffer circles capture the ranging behaviours of territorial raptors |
| topic | Conservation Biology |
| url | http://hdl.handle.net/11427/33229 |
| work_keys_str_mv | AT brinkrene howwelldobuffercirclescapturetherangingbehavioursofterritorialraptors |