Factors affecting presence of vervet monkey troops in a suburban matrix in KwaZulu-Natal, South Africa

Globally with increased urban development, understanding spatial habitat requirements of urban-dwelling wildlife is increasingly important for conservation management. Consequently, we determined the factors that influence the presence of vervet monkeys (Chlorocebus pygerythrus) in urban landscapes. Firstly, we hypothesized that troop size is influenced by seasonality, residence type, proximity to water sources and food provisioning. Secondly, we hypothesized that the resting behaviour of vervet troops is influenced by natural factors, including the presence/absence of raptor nest(s)) and man-made structures including the distance to the nearest main road. Thirdly, we hypothesized that resting by vervet monkey troops would be influenced by the seasons, the distance to the nearest main road (due to the relative openness) and the residence type. Fourthly, we hypothesized that foraging by vervet monkey troops is influenced by food provisioning and bird feeders. Finally, we hypothesized that playing by vervet monkey troops are influenced by the presence/absence of a raptor nest(s), a dog(s) and the residency type. From June 2013 through May 2014 observations were conducted on vervet monkey troops in 20 suburban gardens in the Ethekwini and Msunduzi municipalities of KwaZulu-Natal, South Africa, following a standardized group scan sample method. The observation data were analyzed to determine population-level patterns of landscape use and key suburban landscape features influencing seasonal behaviour, troop size and sex ratios of vervet monkey troops. Mean troop size (29 ± 3.4 (SE) individuals) was influenced by female and juvenile numbers and sex ratio varied across study sites. Behavioural observations (foraging, grooming, playing) were more frequent during winter in gardens with high tree density, and a preference for visitation was found in gardens closer to roads, and where food was provisioned. Probability of foraging, grooming and playing was higher in gardens with greater canopy cover, however this decreased with increasing troop size. Probability of resting decreased with increasing distance from indigenous forest patches and roads. Gardens experienced high levels of raiding. Understanding vervet monkey spatial ecology within a transformed landscape contributes to determining sustainable ways to mitigate conflict and manage their populations in suburbia.