This study evaluates the methods utilised to release and monitor three troops of rehabilitated vervet monkeys (Chlorocebus aethiops) in South Africa. In all cases, monitoring was poor and conducted over a short time-frame disallowing release outcomes to be fully assessed. Wild troops were present at two of the three locations, casting doubt upon sightings of released monkeys and indicating that the release sites chosen were unsuitable and presented disease risks to the wild vervets. Eighty-three percent of monkeys were unaccounted for at the end of monitoring. Any future releases should make use of radio or GPS collars to track the monkeys, have a planned monitoring schedule covering a period of at least one year, collect detailed data on behaviour, demographics and ecology and should follow the IUCN Guidelines for Non-Human Primate Re-introductions.
