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University of Pretoria (2020)

The effects of roads on medium to large mammals within the Kruger National Park, South Africa

Malherbe, Misha

Titre : The effects of roads on medium to large mammals within the Kruger National Park, South Africa

Auteur : Malherbe, Misha

Université de soutenance : University of Pretoria

Grade : Master of Science (MSc) Environmental Ecology 2020

Résumé partiel
Africa’s conservation areas have vast road networks as a result of motorized vehicle game viewing. In conservation areas these roads provide increased accessibility to previously inaccessible areas, often with negative ecological impacts, such as wildlife fatalities and decreased habitat quality and connectivity. Additionally, tar roads often have a greater negative effect on mammal species than dirt roads, altering their spatial distribution and behaviour to a greater extent. The Kruger National Park, South Africa, has 2294 km of public roads within the park, of which 850 km is tarred – carrying a higher traffic density than dirt roads – and 1444 km is dirt. The aim of this study was to compare the ecological impacts of tar and dirt roads on medium to large mammal species in the Kruger National Park, hypothesizing that the tar roads within the park have greater negative impacts on the park’s mammal species. I focused on three response variables : 1. observation likelihoods ; 2. species group sizes and 3. distances to the road, comparing tar to dirt roads. Sampling was done at 1 km intervals, for 430 km of tar and 430 km of dirt roads, in savanna vegetation during the Austral winter of 2017 and 2019. In total 476 sampling points were on tar roads (401 systematic and 75 ad hoc) and 451 on dirt roads (369 systematic and 82 ad hoc). At each sampling point, all observed medium to large mammals, their group size, distance of the closest individual to the road, GPS coordinates, traffic volume and percentage cloud cover were recorded. Chi-square analyses were used to identify associations between species presence and road type. To determine the relationship between group size and road type, as well as the observed distance from the road and road type, Generalised Linear Models (GLMs) were used. The results refute the hypothesis of increased ecological impacts associated with tar roads, as the majority of the commonly occurring mammal species were not disproportionately associated with a specific road type. My results indicated that, as a tourist, one has an equal likelihood of observing the majority of the common mammal species from either road type. The results suggest that the increased traffic intensity of tar roads does not decrease one’s chances of viewing game, as hypothesized.

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Page publiée le 29 avril 2022