Photo: John Burnside
Q: As a resident’s in Simon’s Town perspective where the Smitswinkel troop became increasingly bold and aggressive in procuring “human” food, I’d like to pose the question as to whether the dispersing males are evolving a preference to house raiding than to foraging in their natural environment? Sol as a point in case, after recently being relocated to the Plateau Road side of the mountain is back in Simon’s Town trashing houses. He hasn’t integrated into any of the three troops he has been in contact with as the alpha-males of the troops have rejected his overtures. It appears that he has no appetite for fynbos, or for foraging in the rock pools as the Smits troop do (or perhaps doesn’t have the ability to). Despite those well meaning intentions by those who located him to this area he is not doing well : alone, losing weight and hungry. – Liz Hardman, Simon’s Town.
A: Baboons are renowned for taking advantage of the abundance and concentration of calorie-laden food sources that can be found in the urban environment. This is not to say that baboons are unable to find enough food in natural areas, rather that they opportunistically exchange the energetically-costly and time-consuming forage of natural areas with the easy pickings of garbage and gardens in the urban space. Once baboons have learnt to associate the urban environment with food – as Bart, Sol, and many other lone animals and whole troops have done – they seldom resume natural foraging patterns by choice. For this reason garbage management and the removal of food attractants from urban areas near baboon home ranges is fundamental to improving baboon management.
Your questions about Sol specifically raise some important points concerning the management of dispersing males, and the complications surrounding it. The first is that being a dispersing male is no easy task. As discussed in this week’s blog post, and as you correctly point out for Sol, joining a new troop is difficult. Dispersing males face steep competition from resident males, and integrating into a new troop may take a long time. Consequently dispersing males may spend substantial time on the periphery of the troop and make up for the high costs of trying to integrate with the troop by increasing their consumption of high calorie food items such as human refuse.
Life can be made even more difficult for dispersing males when their dispersal brings them into contact with very different habitats than to what they are accustomed. The majority of dispersers in the Cape Peninsula baboon population are from Tokai, and have spent their lives living and feeding in and around plantations and vineyards. Tokai baboons don’t forage in fynbos – the indigenous vegetation that covers most of the Peninsula – nor on the rocky shore. When these animals disperse they are forced to adjust to entirely novel natural food sources, and they appear to find this exceptionally challenging. John Wayne, Bart and Sol, are all dispersing males from Tokai who have failed to integrate with fynbos troops. Instead all three males seem most attracted to urban areas – behaviour that may have less to do with urban food than with the animals’ inability to source food in indigenous vegetation. This is an area of much needed research. The finding that Sol was only 28kg suggests that he is not in very good condition for an adult male and that he might be struggling to obtain sufficient food in his new fynbos home range. This may explain his frequent forays into the urban areas to obtain high calorie food.
All of these factors present a reality that is not only difficult for the dispersing animal, but also for baboon managers. Managers must to try and strike a balance between the micro-management of individuals and the macro-management of the population – a balance made particularly difficult by severe financial and logistical limitations. At the level of the individual however, it should not be forgotten that despite their proximity to urban areas these baboons are wild animals who are not evolving to eat food (evolution takes place over many generations and requires differential survival of offspring in response to natural selection pressures) but rather adapting within their lifetimes to exploit food of the highest quality which gives them more time for socialising and sex. - BRU
