Compatible social contact should be a part of an environmental enrichment plan to promote psychological well-being of laboratory primates. We continued our investigation of """"""""grooming-contact"""""""" (G-C) bars, which allow physical contact but prevent aggressive pursuit. This design allows grooming and """"""""choice"""""""" of contact (determined by distance to the G-C opening). We investigated whether visual contact of male-female pairs of Macaca fascicularis with other pairs produced changes in urinary cortisol excretion and aggression. We simultaneously investigated whether the use of a familiar rubber toy (Kong) used as cage enrichment and aggression target changed when other pairs were visible, and whether Kong presence affected cortisol and aggression levels. Eight subjects housed in paired cages with G-C bars were observed under conditions of (1) No Contact; (2) Grooming-Contact pairs had grooming contact but saw no other monkeys; (3) G-C Plus Mirror mirrors opposite the bank of eight cages allowed each pair to see three other pairs. Half the subjects had Kong toys during the last 2 weeks of each 4-week condition and half had Kong toys during the first 2 weeks. We measured cortisol levels from urine excreted over 5 hours from 1000h to 1500h and videotaped behavior during the same period (not yet coded). Cortisol level varied by condition and was significantly higher during initial exposure to the other pairs; levels did not differ significantly between G-C (no mirror) and No Contact, nor between Kong and No Kong. Thus, the effects of visual social stimulation on cortisol were significant but transitory. Behavior is being coded from videotapes to determine whether aggression toward other monkeys and chewing of the Kong toy increased with increased social stimulation. Data collected in our previous related studies are under analysis and manuscript preparation continues.
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