Hunting / Farming
Primates in South Africa have garnered a bad reputation over the years. Once legally considered "vermin", these beautiful, engaging, and vastly important species are being eradicated, unapologtically, by the hunting and farming community, for urban expansion, for laboratory studies, the illegal pet trade, and local tribal medicines. With little to no government protection or support, South African primates may not have much time left.
Baboons and Vervets are opportunistic feeders, so any unguarded farm is like Wonka's Chocolate Factory. Many farmers will shoot a monkey on site whether it's feasting on his crops or not, often taking little to no precautions to protect the farm from such animals in the first place.
Hunting of primates remains a legal practice in South Africa. Primates don't yield the greatest meat and are most likely hunted just for pleasure and a photo opportunity or trophy (see above photo).
Many of Riverside's casualties are a result of irresponsible hunting/culling or farmers shooting invaders. They shoot the mothers and lack the nerve to destroy the infants, often opting to keep them as a pet.
Baby baboons and Vervet monkeys are often purposely orphaned or bought/sold to be kept as pets, as they are quite cute and helpless as infants.
Once they reach a couple of months of age or so, and gain some independence, they become destructive at best, and at worst can become frustrated and aggressive, especially when isolated from a natural environment and troop setting.
Pet primates are often destroyed by their owners when they become unmanageable. The greater majority of Riverside's residents are made up of disgarded pets.
Baboon raids on human dwellings have become highly publicized in recent years. Due to urban expansion, there is less and less space for baboons and Vervets to live and find food. Human tendency to irresponsibly dispose of waste food has attracted these opportunistic and highly adaptive creatures into human neighborhoods to seek easy food sources ("Fast Food" for monkeys, if you will). Many times, individuals complaining of primate conflict in this manner admit to having caused the problem initially by hand feeding the animals because they thought they were cute or drew in public admirers.
Simply locking doors and windows, and having lockable rubbish bins and burglar bars (which are standard in South Africa) would greatly reduce the number of raids on these homes by primates.
Vervet monkeys and baboons are still commonly used for laboratory testing all over the world. Recently the esteemed Harvard University was penalized for cruelty against lab baboons at their New England Medical Center (The Boston Globe) They undergo horrific and painful tests, and vivisection procedures all over the world.
It is common practice within a few South African cultures to use animals for traditional medicine or witchcraft. All types of South African wildlife, including primates, are kept in inhumane conditions to eventually be killed and mutilated (not necessarily in that order) and used for "Muti".