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Taxonomy and Conservation of Trapdoor Spiders in Gauteng Province, South Africa.
Thesis(PhD (Zoology))--University of Pretoria, 2016.
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| Format: | Thesis |
| Language: | English |
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2026
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| _version_ | 1867613497172426752 |
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| access_status_str | Open Access |
| author2 | Scholtz, Clarke |
| author_browse | Scholtz, Clarke |
| author_facet | Scholtz, Clarke |
| collection | Thesis |
| description | Thesis(PhD (Zoology))--University of Pretoria, 2016. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/110077 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:37:05.077Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2026 |
| publishDateRange | 2026 |
| publishDateSort | 2026 |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/110077 Taxonomy and Conservation of Trapdoor Spiders in Gauteng Province, South Africa. Scholtz, Clarke ianicus.za@gmail.com Robertson, Mark P. Engelbrecht, Ian Andrew Biodiversity Optimization Survey design Threatened species Thesis(PhD (Zoology))--University of Pretoria, 2016. Systematic conservation planning has become standard practise for prioritising areas for biodiversity conservation and protected area network expansion. Invertebrates comprise the vast majority of terrestrial animal biodiversity, but they are largely ignored in most systematic conservation planning projects because the data needed to include them in the process simply don’t exist. This is especially the case for cryptic, less charismatic taxa. This study aimed to improve the state of knowledge of a particularly cryptic group of arthropods, the trapdoor spiders of the families Cyrtaucheniidae, Ctenizidae and Idiopidae, for the purposes of systematic conservation planning in Gauteng Province, South Africa. A method was developed for assessing the accuracy of the current taxonomy, a concept termed taxonomy resolution, to determine the likelihood that species boundaries might change with ongoing taxonomic work, and hence how currently described species should be interpreted in conservation status assessments. The results showed that the taxonomy of South African trapdoor spiders is poorly resolved with a high likelihood of species complexes and synonomies in known species as well as new species discoveries. These results were confirmed in a taxonomic study of the genus Stasimopus in the Pretoria area where three new species were described, and morphological homogeneity amongst females of Stasimopus robertsi Hewitt 1910 and S. hewitti sp.n. had resulted in misinterpretation of the conservation status of S. robertsi in previous conservation status assessments. Sampling trapdoor spiders to collect material for taxonomic and conservation work is challenging because of their cryptic behaviour of camouflaging their burrows. A study understaken to assess optimal sampling methods showed that pitfall trapping was the most effective method for collecting adult males, which are important for identifications and taxonomic work, and that male activity was highest under conditions of high soil moisture following rainfall. Different species were found to have discrete activity periods within the year, and significant sampling effort is required for a high probability of sampling rare species at a site. Some species were also found to be active at different times of the year at different sites. Therefore, pitfall trapping should be conducted throughout the year following rainfall events in order to obtain complete or near-complete species inventories at survey sites. Also important in designing surveys for cryptic invertebrates is where sampling should take place. The Environmental Diversity (ED) method was investigated as an approach to site vii selection for large scale biodiversity surveys. Previous uncertainties indicated in the literature regarding the value of this method were resolved and it was found that ED outperforms other methods for selecting sites in terms of the number of species sampled. An example of how the method may be applied is presented for reptiles in South Africa, and ED was also used to select additional survey sites for trapdoor spiders in Gauteng Province. In conclusion, surveys of trapdoor spiders in Gauteng Province have shown that there is significantly more species diversity than previously thought, but that there is still insufficient data for robust species conservation status assessments. This presents an ongoing impediment to conserving trapdoor spiders effectively. However, sampling methods for these spiders have been improved substantially and provide a valuable foundation for further survey work should the resources be made available to do so. It is recommended that taxonomic revisionary work be undertaken in parallel with field surveys to provide the information necessary for species conservation assessments. The results presented in this thesis provide a model for undertaking surveys of other cryptic invertebrate taxa for conservation purposes. Zoology and Entomology PhD (Zoology) 2026-05-15T17:26:14Z 2026-05-15T17:26:14Z 16/07/12 2016 Thesis http://hdl.handle.net/2263/110077 en application/pdf |
| spellingShingle | Biodiversity Optimization Survey design Threatened species Taxonomy and Conservation of Trapdoor Spiders in Gauteng Province, South Africa. |
| title | Taxonomy and Conservation of Trapdoor Spiders in Gauteng Province, South Africa. |
| title_full | Taxonomy and Conservation of Trapdoor Spiders in Gauteng Province, South Africa. |
| title_fullStr | Taxonomy and Conservation of Trapdoor Spiders in Gauteng Province, South Africa. |
| title_full_unstemmed | Taxonomy and Conservation of Trapdoor Spiders in Gauteng Province, South Africa. |
| title_short | Taxonomy and Conservation of Trapdoor Spiders in Gauteng Province, South Africa. |
| title_sort | taxonomy and conservation of trapdoor spiders in gauteng province south africa |
| topic | Biodiversity Optimization Survey design Threatened species |
| url | http://hdl.handle.net/2263/110077 |