The impact of habitat structure on reptile occurrence in a fragmented tropical landscape

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dc.contributor.authorEvans, Aleandra
dc.date.accessioned2019-08-29T09:33:55Z
dc.date.available2019-08-29T09:33:55Z
dc.date.issued2018
dc.descriptionA dissertation submitted to the faculty of science, University of the Witwatersrand, in fulfillment of the requirements for the degree of Master of science, Johannesburg, 2018en_ZA
dc.description.abstractDefining the spatial distributions of species with regards to habitat selection and landscape structure is an important part of biogeography, ecology and conservation research. I investigated reptile occurrence and community structure in two patches of dry forest in north western Madagascar using detection/non-detection data collected on repeated transect surveys for four years. A Bayesian hierarchical occupancy model and multispectral satellite imagery were used to assess the effects of vegetation structure, proximity to human development and edge proximity on the site presence of 37 squamate species in the context of taxonomic family and Threat Status. Mean species richness was highest at sites within a forest patch (23 (4, 30)). Sites with dense green vegetation promoted the highest levels of reptile occupancy among the Chamaeleonidae and Gekkoniidae families (with regression coefficient estimates up to 0.75 (0.12, 1.53)) and all species were more likely to occur at sites closer to the forest patch periphery. The Boidae had the widest 95% CRI for the regression coefficient estimates representing the effects of habitat variables on occupancy, indicating that they are highly variable in their habitat use. The regression coefficient estimates of mean reptile occupancy had 95% credible intervals (CRIs) including zero due to high variability between species. The proximity to roads did not have a statistically significant effect on any of the species, and Uroplatus guentheri was the only species which showed a significant preference for being further from a settlement (0.81 (0.05, 1.77)). The findings demonstrated the importance of using caution when assessing Threat Status at a regional level and suggest that the Red List’s measure of Population Trend may be significantly influenced by imperfect detectionen_ZA
dc.description.librarianMT 2019en_ZA
dc.format.extentOnline resource (106 leaves)
dc.identifier.citationEvans, Alexandra Mary, (2018) The impact of habitat structure on reptile occurrence in a fragmented tropical landscape, University of the Witwatersrand, Johannesburg, https://hdl.handle.net/10539/27925
dc.identifier.urihttps://hdl.handle.net/10539/27925
dc.language.isoenen_ZA
dc.subject.lcshReptiles--Ecology
dc.subject.lcshAmphibians--Conservation
dc.titleThe impact of habitat structure on reptile occurrence in a fragmented tropical landscapeen_ZA
dc.typeThesisen_ZA
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