Eleven baboons who had been singly housed indoors for an average of 5 years
were moved to outdoor social groups in an attempt to provide a more specie
s-typical environment and reduce high levels of abnormal behavior. Nine of
the baboons were observed while in single housing and, over a 6-month perio
d, while housed outdoors socially to document long-term changes in behavior
. Abnormal behavior decreased significantly from an average of 14% of the o
bservation time in the single cages to 3% in the sixth month of social hous
ing. Cage manipulation and self-directed behaviors also significantly decre
ased, while social behavior, enrichment-directed behavior, and locomotion i
ncreased in social housing. Baboons that had been in long-term indoor singl
e housing were able to reproduce and form stable social groups without inju
ry. This study provides evidence that even behaviorally disturbed nonhuman
primates can be successfully rehabilitated to live in social groups.