Individual Caging and its Problems (photos 1-11)

Individual caging is a species-inadequate housing condition for macaques


  Photo 1: "Single or individual caging systems are [still] the basic staple housing used for primates" [Rosenberg & Kesel, 1994; cf., National Institutes of Health, 1991; National Research Council (NRC), 1998], regardless of the fact that primates have "social needs" [Animal Welfare Institute, 1979] which federal law stipulates "must" be addressed in the "environmental enhancement plan" [United States Department of Agriculture (USDA), 1991]. "Having access to one or more [compatible] companions may be the most effective way to foster psychological well-being in most nonhuman primates" [Novak & Suomi, 1991]. The International Primatological Society admonishes that "unless absolutely essential, primates should not be housed alone in a cage on a long term basis (more than 30 days)" [IPS, 1993]. "Social deprivation should not be considered any more normal than ... water or food deprivation" [de Waal, 1991].

Photos 2 & 3: Being housed in a single-cage is boring (photo 2) and depressing [Lilly et al., 1999] for any social animal, particularly for intelligent animals such as primates (photo 3).


 

Photo 4: Forceful confinement in a single-cage is a frustrating experience for primates, because there is no option of changing this disliked situation.

Photos 5 & 6: "Knowing that most primates benefit from social interactions, it should be obvious that they can be harmed by a lack of social interaction" [NRC, 1998]. Single-cage imprisonment is so frustrating for human primates that many inmates (photo 5) "prefer to maim themselves rather than stay there" [Yaroshevsky, 1975]. The same may also apply for nonhuman primates (photo 6) who often show self-biting behavior when being confined in single cages. "Prolonged individual housing is probably an influential contributing factor" for this behavioral pathology [NRC, 1998].




Photos 7* & 8a: Self-biting behavior in single- caged rhesus macaques usually goes unnoticed, because subjects 'only' show alopecia and abrasion at the sites of biting (photo 7, right wrist of this animal; photo by Lisa Knowles).

In approximately 10 out of 100 individually housed animals, however, the problem cannot be overlooked (photo 8) because the self-injurious behavior results in lacerations requiring veterinary treatment [Jorgensen et al., 1998; Novak et al., 1998; Macy et al., 1999].


Photo 8b: Individually housed rhesus male engaged in stereo- typical self-biting behavior (Photo by Matt Rossell).

 

Photo 9*: "Solitary confinement is a severe punishment even for monkeys" [Sakol, 1993].

 

Photos 10 & 11*: Primates – human and nonhuman primates alike – need social contact and social interaction for psychological comfort and well-being [Shively et al., 1989; NRC, 1998; Lilly et al., 1999]. "

A compatible conspecific probably provides more appropriate stimulation to a captive primate than any other potential environmental enrichment factor" [IPS, 1993].

  Group-housing (photos 12-14)

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