Canadian Council on Animal Care 1993. Guide to the Care and Use of Experimental Animals, Volume 1, 2nd Edition. Canadian Council on Animal Care, Ottawa, Canada.

A thorough guide to the species-appropriate housing and handling of nonhuman primates. Differences in light, temperature, and airflow between locations on a cage rack can affect experimental results and should be minimized by either rotating cages through different positions on a rack, or by assigning animals to cages bases on a table of random numbers (p. 23). All animals must be observed at least once daily (p. 43). The social needs of animals used in research, teaching, or testing, should be given equal consideration with environmental factors such as lighting, heating, ventilations and containment (caging). Particularly in the case of singly housed animals, daily observation provides an alternative from of social contact for the animal and commonly facilitates handling in that the animal becomes accustomed to the human presence (p. 51). Most animals should not be housed singly unless required by medical condition, aggression, or dictates of the study. Singly housed animals should have some degree of social contact with others of their own kind (p. 52). In the interest of well-being, a social environment is desired for each animal which will allow basic social contacts and positive social relationships. Social behaviour assists animals to cope with circumstances of confinment (p. 52). Restraint procedures should only be invoked after all other less stressful procedures have been rejected as alternatives. ... Physiological, biochemical and hormonal changes occur in any restraint animal ... and investigators should consider how these effects will influence their proposed experiments (p. 95).