
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 programs
to their original habitat.

Outside West Africa there
are not more than 31 Roloway guenons kept in European Zoos, with the
Zoo Mulhouse 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, some of them in Twycross Zoo (England). The Zoo Heidelberg is the
only zoo in Germany, which houses 6 individuals, thus keeping almost a
quarter of the total captive population. The Diana guenon can be found
more commonly in European zoos but also this species is regarded as
rare in captivity.
There were 45 White-naped
mangabeys in 10 European zoos in 2000. 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 of White-naped mangabeys.