Effects of Monitors
THE INTERFACE BETWEEN SOCIOECOLOGY AND MANAGEMENT OF CHACMA BABOONS (PAPIO URSINUS) IN THE CAPE PENINSULA, SOUTH AFRICA.
Summary of project
Baboons have been well studied throughout Africa. Their ability to live in a wide variety of habitats, primarily due to dietary and behavioural flexibility, has allowed them to successfully adapt to encroaching urbanization and the transformation of natural areas. In many instances, baboons have incorporated human-derived food into their overall foraging repertoire. This has resulted in conflict between humans and baboons, which carries financial and emotional costs for humans and leads to increased rates of mortality and injuries in baboons. Baboon troops living on the Cape Peninsula of South Africa provide an excellent example of this scenario. Troops living in close proximity to human settlements are generally regarded as “pests” as they forage on the contents of rubbish bins, fruits and vegetables within fenced gardens, and occasionally enter houses and grocery stores. Once inside a home or store, the baboons often make a considerable mess and damage property and goods.
One potentially successful long term solution to human-baboon conflict in the Cape Peninsula was the introduction of baboon monitors in 2000 to troops that regularly raided residential areas. Managed by Cape Nature and the Cape Peninsula Baboon Management Team (BMT), the function of these monitors is to actively herd baboons out of residential areas and thus prevent them from accessing human derived food sources. The monitors achieve this either by blocking the movement of the baboons or by driving them away from the urban areas by shouting, clapping, waving sticks and occasionally throwing stones. Often, the baboons respond with only minimal coaxing and begin moving in the dictated direction. While a preliminary study (Kansky and Gaynor 2000) indicated that baboon monitors are effective in their goal of reducing raiding, no study had addressed the impact of this management strategy on baboon behaviour or socioecology.
Aims
In this study I had two main objectives: (1) to assess the effects of season on the activity budget, diet and habitat use of a semi-commensal, monitored troop of a chacma baboons (Da Gama) living in a Mediterranean climate; (2) to compare the activity budget, diet and habitat use of a monitored versus un-monitored troop of chacma baboons (Plateau Road) within one geographic area while controlling for as many variables as possible. It was my intention to use these data to inform the Peninsula Baboon Management Team of the effects of monitors on the socioecology of baboons and where applicable to make recommendations for improved management which would equate to reduced raiding while minimising the effects of monitors on the natural behaviour of Peninsula baboons.
Results
The results of this study revealed differences between the two study troops. In particular, the non-monitored, free-ranging Plateau Road troop exhibited seasonal differences in its activity budget and diet (van Doorn et al., 2010). Contrastingly, there was no effect of season on the time that the Da Gama troop allocated to feeding and their diet did not vary seasonally, with the exception of raided food items which increase in winter months. With regard to habitat preference, both troops exhibited a marked preference for alien trees as sleeping sites and alien vegetation for foraging. Furthermore, both troops utilised the abundant indigenous vegetation significantly less than predicted. The Plateau Road troop used habitat types evenly in relation to their overall activity budget, while the Da Gama troop’s activities were highly variable according to habitat. The two troops also differed in their patterns of home range use, daily distances travelled, travel speed and seasonal variation in habitat use.
The results of this study provide a deeper understanding of the activity budget and habitat utilization of two troops of baboons living in a transformed environment subject to the dual constraints of season and day length. My results indicate that the management strategy of employing monitors significantly reduces the presence of baboons in the urban area and limits their opportunities for raiding. However, the monitors’ use of a “herd-and-then-hold” technique did have a significant influence on how baboons utilize their physical environment, changing their habitat usage patterns and prohibiting the troop from varying their foraging areas and diets seasonally. Intensive, unsystematic herding acted as a significant constraint on baboon behaviour, particularly by reducing the time the baboons spent feeding. High levels of herding may have resulted in higher stress levels as indicated by increased self-grooming. In conclusion, my study shows that baboon monitors are a successful management tool to reduce raiding, but that substantial improvements can be made to how the baboons are herded to reduce potential detrimental effects on the troop.
Publications
van Doorn A and O’Riain MJ. (in review) To herd and to hold: are monitors an effective method to reduce conflict between humans and primates and do they affect the behaviour, movement patterns and diet of chacma baboons (Papio ursinus) in the Cape Peninsula of South Africa? American Journal of Primatology.
van Doorn A, O’Riain MJ, and Swedell L. 2010. The effects of extreme seasonality of climate and day length on the activity budget and diet of semi-commensal chacma baboons (Papio ursinus) in the Cape Peninsula of South Africa. American Journal of Primatology 72: 104-112. PDF
van Doorn, A.C., O’Riain, M.J., Swedell, L. Behaving, but at what cost? The effects of a management technique on a chacma baboon troop in South Africa. Proceedings of the XXIIIth Congress of the International Primatological Society (talk at 2010 meeting of the International Primatological Society).
van Doorn A and O’Riain MJ. 2009. The efficacy of a management strategy and its impact on chacma baboons (Papio ursinus) in the Cape Peninsula of South Africa. American Journal of Primatology 71(1): 70 (talk at 2009 meeting of the American Society of Primatologists).
van Doorn A (2009) The Interface Between Socioecology and Management of Chacma Baboons (Papio ursinus) in the Cape Peninsula, South Africa. Ph.D. thesis, University of Cape Town.
