The first results of a project using radio collars to track the movement of baboons on the Cape Peninsula show that the primates spend 80 percent of their time foraging in the wild and only 20 percent in urban areas - far less than researchers thought.
Results also show that the baboons prefer the lower-lying areas of the Peninsula - the same areas preferred for housing developments - which means an increase in conflict between people and baboons as these areas become built up.
When researchers replaced a malfunctioning collar on a baboon called Jimmy last week, they found the collar had not even left an impression in the animal's fur after nearly three months.
Justin O'Riain, who heads UCT's baboon research unit, said: "That was fantastic to see. We weighed him and he had not lost any weight either."
The fitting of collars to baboons has been controversial, with some saying the collars would harm the animals.
The aim of the research is to establish the home ranges of the baboons, their movement patterns, diet and which habitats and levels of altitude they prefer. The data will help with baboon management on the Peninsula.
"The data suggesting baboons prefer lower altitudes is very important because the lower areas are exactly where people like to build. If anyone develops in the baboon's known home range, you will get an escalation in conflict," O'Riain said.
He said from the number of reports of baboons raiding houses, he would have thought they spent more of their time than just 20% in urban areas.
The radio collars indicate that the Smitswinkel troop has a bigger range than expected, from the Cape Point entry gate to Simon's Town.
"We realised that the Smitswinkel group go on quite long journeys and are away for a week or so, so residents drop their guard and leave windows open. Suddenly the baboons are back. We can watch their movements on our computers here at UCT and send an e-mail to the neighbourhood watch to alert them that the baboons are back," O'Riain said.
Catching Jimmy from the Waterfall troop to replace the radio collar was fairly easy. Fruit was put in a cage and once he was inside eating, the gate was lowered. Jimmy was anaesthetised using a pole-dart.
"If you handle an animal in front of the troop you're in trouble, so we needed to get him inside, but Bongo, the alpha male, charged us when we tried to carry the cage inside. This is the guy who normally likes to beat up Jimmy," O'Riain said.
They rolled some apples to Bongo to distract him, but he merely stuffed them in his cheek pouches and resumed the charge. "So we cut up the apples into small pieces, scattered them around, and while Bongo was busy picking those up it gave us the 30 seconds we needed to get the cage inside."