Die PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 125 
cages, enclosures, holding chairs, etc., can be designed. One must 
understand the social composition of the species concerned; each 
species has its own pattern of social behavior that must be understood 
if the animals are to be kept in captivity as healthy breeding units. 
One must know the technical details of the microclimate, the tempera- 
ture-ranges, and the humidity. One must know the physical nature of 
the environment: Do these monkeys live among the small flexible 
branches of the canopy, on the stout branches near the trunk, or on 
the trunk itself? Only by finding the answers to these questions can 
one hope to provide, artificially, something approaching a realistic 
(though obviously not a normal) environment for the animal con- 
cerned. To provide a captive animal with an adequate, suitable 
environment is not only humane but sound common sense. Many of 
these problems are now being tackled in the Regional Primate Centers 
in the United States, but the basic research necessary for a full aware- 
ness of the welfare and husbandry of a wide range of primates will take 
many years of detailed and imaginative research. 
Boredom in captive primates is another very serious, but generally 
unappreciated, problem. In the wild, most of the primate’s working 
hours are spent in search of food. If, in captivity, it is deprived 
of this occupation, it has no normal substitutes. It develops behavioral 
aberrations such as coprophagy, masturbation, and stereotyped 
behavior patterns like staring into space for long periods, clasping 
the head or body and rocking to and fro, and hopping from one foot 
to another. These are typical withdrawal patterns seen in deprived 
primates, human or nonhuman. It has been said that “a solitary 
chimpanzee is no chimpanzee at all.” Much of the boredom can be 
alleviated by caging monkeys in social groups so that normal social 
interactions, such as grooming activities among adults and play 
among infants and juveniles, can help to compensate for the lack of 
active food-getting. Ideally, some type of food-getting activity should 
be devised; for example, it should be possible to mix food pellets or 
natural food objects into the deep gravel or sandy floor surface of the 
day cage in order that the animals can spend many hours of the day 
digging and hunting for food. In this way an element of uncertainty 
and variety can be introduced into the daily life of the animal. Higher 
primates need, above all, intellectual employment and the stimulation 
of unusual objects or events. 
The principal aim of the research will be to obtain measurements 
of tolerance of monkeys to captive conditions in laboratories, zoos, 
and in “free-ranging” captivity. The following aspects of tolerance 
should be considered: 
1. Climatic: Response to high and low temperatures and humidity levels; 
habitus changes associated with different climatic conditions. 
