Survey of Behavioral Indices of Welfare in Research Chimpanzees (Pan troglodytes) in the United States.

Chimpanzees demand specialized housing and care and the highest degree of attention to animal welfare. The current project used a survey method to collate information on chimpanzee housing and behavioral indices of welfare across all 6 of the chimpanzee research facilities in the United States. Data were compiled on 701 chimpanzees ranging from 2 to 62 y old (mean age, 26.0 y). All chimpanzees except for one were socially housed; the median group size was 7 animals, and group sizes ranged from 1 to 14. All of the subjects had access to outdoor spaces each day. Daily access to a natural substrate in the chimpanzee's enclosure was available for 63.8% of the subjects. Overall, 94.1% of the chimpanzees used tools to acquire food, 48.1% built nests, 75.8% copulated, and 83.3% initiated grooming bouts. The following atypical behaviors were reported most often: rocking (13.0%), coprophagy (10.0%), and stereotyped behaviors other than rocking (9.4%). There was widespread evi- dence of positive animal training techniques, with nearly all (97.7%) subjects reported to generally voluntarily cooperate with shifting in their enclosure, and 72.2% were reported to present for an injection of anesthetic. We include some comparison between these findings and data describing zoo-housed chimpanzees. In addition, we discuss survey findings in reference to recommendations made by the NIH Working Group on the Use of Chimpanzees in NIH-supported Research. The current survey assessed a larger sample of chimpanzees living under human care than has been published previously. This broad analysis can help to guide future improvements in behavioral management to address behavioral problems or deficits.

Pair housing of Vervets/African Green Monkeys for biomedical research.

Vervets, also known as African green monkeys, are a nonhuman primate species widely used in biomedical research. However, there are currently few references available describing techniques and rates of success for pair-housing this species. We present data from four cohorts of vervets from three different facilities: (i) the Wake Forest Vervet Research Colony (VRC; n = 72 female pairs, n= 52 male pairs), (ii) the University of Louisiana at Lafayette-New Iberia Research Center (UL-NIRC; n = 57 female pairs, n = 54 male pairs), (iii) the Tulane National Primate Research Center (TNRPC; n = 18 male pairs), and (iv) a cohort of imported males (n = 18 pairs) at Wake Forest. Compatibility was measured at 14, 30, and 60 days following introduction. Success rates for pair-housing at 14 days ranged from 96% to 98% for females and 96% to 100% for males at the VRC and UL-NIRC but were lower in the smaller imported male cohorts (TNPRC: 50%; WF: 28%). Among the UL-NIRC cohort and VRC male cohort, most of the pair separations after 14 days were due to reasons unrelated to social incompatibility. In contrast, a large proportion of TNPRC and imported male pairs successful at 14 days required separation within 60 days due to incompatibility. Multiple logistic regressions were performed using cohort, mean age of pair and weight difference between pair-mates as potential predictors of compatibility at 14 days. All three predicted the 14-day outcome in males but not females. A separate analysis in the VRC cohort found no evidence that prior familiarity in a group setting influenced outcomes. Variations in success rates across cohorts may have been influenced by introduction methodology. Behavioral differences between vervets and macaques, coupled with our findings, lead us to theorize that the gradual introduction techniques commonly implemented to pair house macaques may not be beneficial or suitable for this species. Am. J. Primatol. 79:e22501, 2017. © 2015 Wiley Periodicals, Inc.

An evaluation of nest-building behavior by sanctuary chimpanzees with access to forested habitats.

All of the great apes build nests, but captive chimpanzees rarely have vegetation from which to build nests. The forested environment at Chimp Haven does allow captive chimpanzees to build nests of natural vegetation. Between February 2007 and December 2010, 238 nests were found in 2 forested habitats. Nests were made of naturally available vegetation, and more nests were made on the ground than in the trees (Z = 7.27, p < 0.001); nests were also built in the interior forest rather than on the periphery (Z = 7.06, p < 0.001). There was no correlation between the number of months in the habitat and the nests built per chimpanzee (rs = -0.07, p = 0.52). More nests were observed when more wild-born females were in the group (rs = 0.27, p = 0.01), and during warmer temperatures (rs = 0.45, p < 0.001). These findings support the goal of naturalistic environments in suitable climates for captive chimpanzees.