White rhinoceros populations in the Eastern Cape: distribution, performance and diet

White rhino populations did not occur historically in the Eastern Cape, South Africa (Skead 2007). They have, however, been introduced into a number of reserves within the Eastern Cape for reasons such as conservation, ecotourism and hunting. Based on the literature on the species, it was hypothesized that white rhinoceros would have been introduced in grass-rich habitats, as they are bulk grazers. White rhinoceros populations were further assessed in terms of population establishment by outlining their distribution and performance since introductions and this was done by extracting intercalving intervals from the literature of native populations and comparing such to the Eastern Cape intercalving intervals, extracted from data obtained from landowners. Finally, the diet of white rhinoceros was quantified, in order to identify plant species potentially at risk from white rhino herbivory using Shamwari Private Game Reserve as a study site. The distribution of white rhino in the Eastern Cape varies in terms of habitat and vegetation types. The majority (62%) of white rhino are located in grass-poor habitats and are primarily there for ecotourism purposes with only a small percentage kept for conservation purposes in the state reserves. Limited data for intercalving intervals of the white rhino in Eastern Cape are comparable to those of populations in the natural range. The ex situ conservation of white rhino in the Eastern Cape proved to be a success as population numbers have increased markedly since the first survey was conducted (Buijs 1999). The diet section of this study showed that white rhino are highly selective grazers even in a grass-limiting habitat which is dominated by browse. Twenty-five principal dietary items were identified in their diet, with only six being preferred in autumn. These are thus the plant species that could be the most vulnerable to white rhino herbivory. Supplementary food provision plays a big part of the feeding scheme of white rhino in Shamwari Private Game Reserve during the winter season, revealing the little confidence that the management has on natural resource availability to the animals at this time. These findings support the value of the Eastern Cape for ex situ conservation of white rhino, and highlight plant species potentially at risk. There is a need for further research on the population performance of these animals, and the plants identified here need to be monitored to assess white rhino impact on the vegetatio

How do free-ranging domestic herbivores reduce competition within owner-determined herds?

Group size and competition are key drivers of foraging behaviour in social animals. With seasonal changes in food quality and availability, comes changes in the type (scramble or interference) and degree of competition (aggression or none). One way that animals can deal with these variations is by living in groups where the benefits of the group size outweigh the costs. However, this is generally not possible with domesticated animals, as group sizes are determined by owners. Thus, within these groups, animals have to make behavioural adjustments to reduce competition. To determine how domestic indigenous veld goats (Capra hircus), living in different sized owner-determined groups, dealt with seasonal variations in food availability and quality, and thus competition, we recorded their foraging behaviour. Specifically, we documented patch-joining events, herd splits, and interindividual distances (IID). We found that goats only joined the patches of other herd members during the wet season, when food was more readily available. In addition, we found that large herds split into a number of smaller subherds (comprising ca. 15 individuals) that were similar in size to the unsplit small herds. Furthermore, these splits primarily happened during the dry season and were more frequent in large herds compared to small herds. Finally, IID increased in the dry season for both small and large herds, likely as a way to reduce interactions while feeding. Yet, individuals in large herds maintained larger IID than individuals in small herds, suggesting a greater attempt to reduce interactions in large herds. The fact that the large owner-determined herds had to elicit a greater number of behaviours, suggests greater levels of competition in these herds in the arid savanna system. These results suggest that by using behavioural indicators such as IID or herd splits, owners could monitor competition within their herds and determine when it would be better to keep their goats in smaller herd sizes.The University of KwaZulu-Natal, National Research Foundation (Grant: 77582 A.M.S) and National Research Foundation Thuthuka Funding Instrument (Grant: 94021).https://www.elsevier.com/locate/applanim2019-08-01hj2018Mammal Research InstituteZoology and Entomolog