A range of species exploit anthropogenic food resources in behaviour known as ‘raiding’. Such behavioural flexibility is considered a central component of a species’ ability to cope with human-induced environmental changes. Here, we study the behavioural processes by which raiding male chacma baboons (Papio ursinus) exploit the opportunities and mitigate the risks presented by raiding in the suburbs of Cape Town, South Africa. Ecological sampling and interviews conducted with ‘rangers’ (employed to manage the baboons’ space use) revealed that baboons are at risk of being herded out of urban spaces that contain high-energy anthropogenic food sources. Baboon-attached motion/GPS tracking collars showed that raiding male baboons spent almost all of their time at the urban edge, engaging in short, high-activity forays into the urban space. Moreover, activity levels were increased where the likelihood of deterrence by rangers was greater. Overall, these raiding baboons display a time-activity balance that is drastically altered in comparison to individuals living in more remote regions. We suggest our methods can be used to obtain precise estimates of management impact for this and other species in conflict with people.
EnvironmentData
A map of the study region was divided into 150 m2 grid cells (n = 200). We then defined the habitat type of the cell, estimated the risk of deterrence by baboon rangers and food rewards for each cell. The risk of baboons being deterred by ‘rangers’ range from likely deterrence (red, score 22) to passive monitoring (green, score 0). The energy available from potential food items is presented as the mean kcal/bite ranging from 0, to 22.6. Cells were categorised as one of five broad habitat categories according to their dominant features (fynbos, trees, meadows, vineyards and urban areas) based on researcher knowledge of the site and images from Google Earth (accessed 06/06/2014).
TimeBudget
To compare focal baboon activity budgets to those published in the literature, we conducted 30 minute direct focal observations of each male (n=311; mean +/- sd per baboon = 51.8 +/- 0.7). At each minute we recorded the baboons’ instantaneous behaviour (classified as resting (Res), grooming (Soc), foraging (For) or travelling (Mov)). The total amount of observations per male was given as (Obs).
CollarData
Eight adult male baboons within our focal troop were cage-trapped before being sedated by a certified veterinary and fitted with a custom-built tracking collar. Collars weighed less than 2.5% of the body mass of the baboons and were approved for use by Swansea University Ethics Committee (Swansea University IP-1314-5). Collars were equipped with sensors recording GPS every 5 minutes and acceleration in 3 axes at 40 Hz. Data were recorded from 7:30 am to 6:00 pm and only data recorded between sunrise and sunset according to the South African Astronomical Observatory were selected resulting in 6,325 fixes. Any pair of successive fixes more than 1 km apart were assumed to be errors, and removed, resulting in 6,274 fixes. Ad-hoc checks of the data where baboons cross known landmarks indicate positional accuracy of <10m for processed GPS data. Latitudes and longitudes are given in WGS84. Acceleration was recorded continuously at 40 Hz for 5 individuals and at 20 Hz for one individual (LM). Acceleration raw data were first decomposed into static and dynamic acceleration with a running mean of two seconds then we calculated the Vector of the Dynamic Body Acceleration (VeDBA) calculated from dynamic acceleration data. We superimposed the GPS data with (1) the map of the risk of deterrence, obtained via interview with baboon rangers (scores ranging from 0 for low risks of being deterred to 22 for high risks); (2) the habitat map were habitats were categorised as one of five broad habitat categories (fynbos, trees, meadows, vineyards and urban areas) based on researcher knowledge of the site and images from Google Earth (accessed 06/06/2014).
