Future breeding females retained within their maternal group will reach reproductive age by about four years old and will then produce roughly one baby every 20 months. The offspring of dominant females will eventually assume dominance within the group so maintaining a stable hierarchy throughout the life of the breeding group. This necessitates the males moving, to avoid father/daughter mating. Moving males has the added benefit of maintaining productivity. Where possible, the female offspring are retained within groups so maintaining mother/daughter relationships. Groups range in size from 5-10 females and one male. The age of removal of animals from the group is based mainly on health and productivity.
Young animals destined for supply to scientific establishments are removed from their natal group at around two, and never less than one year old. They are normally supplied at the age of between 3-6.
Animals are all individually named, and the member of staff which first identifies the sex of a newborn gets to choose the name. During the first health screen they will normally be tattooed with an abbreviation of their name. This is in order to ensure absolute certainty in identifying individual animals. The tattoos are evident in some of the images and videos on these pages.