
Modern zoological gardens take on more and more responsibility to
provide a shelter for endangered animals. The offspring of these
animals can potentially be re-introduced through conservation
programmes into their native habitat.

Outside
West Africa there are not more than 31 Roloway Guenons kept in European
Zoos, with the Mulhouse Zoo coordinating the official studbook for this
sub-species. This captive population was formed from 11 founder
individuals originally kept as pets in Togo. They were donated to
Mulhouse Zoo with the support of the IUCN in order to establish a
breeding programme. Most of these animals now live in French zoos, with
some at Twycross Zoo (England). Heidelberg Zoo is the only facility in
Germany, which houses 6 individuals, thus housing almost a quarter of
the total captive population. The Diana guenon can be found more
commonly in European zoos although this species is regarded as rare in
captivity.
There were 45 White-naped mangabeys in 10 European zoos as of 2008. The
most successful breeding groups are in Rome (Italy) and Paris (France)
as well as in Jerez and Barcelona (both in Spain) and in Landau
(Germany). Barcelona Zoo keeps the official stud book for this species.