Survey of environmental enhancement programs for laboratory primates (2007)

Baker, K. C., Weed, J. L., Crockett, C. M. et al.

Abstract

Here we report the results of a 2003 survey that was sent to individuals overseeing enrichment programs at a variety of primate research institutions. Data were obtained on the management of 35,863 primates in 22 facilities. While most primates were reported to be housed socially (73%), social housing for indoor-housed primates appears to have changed little over the past 10 years. Research protocol issues and social incompatibility were commonly cited constraints. Implementation of feeding, manipulanda, and structural enrichment was relatively unconstrained, and contributions to these aspects of behavioral management generally included individuals in a wide variety of positions within a facility. In contrast, enrichment devices were used on a less widespread basis within facilities, and positive reinforcement programs that involved dedicated trainers were rare. Social Housing: We focused on the indoor population to assess the current status of efforts to reduce the use of single housing in research. With outdoor-housed primates excluded from the analysis, our sample included 17,663 individuals, 46% of which were housed socially. Feeding Enrichment: All facilities included feeding enrichment in their plans. No facilities provided fewer than half (1-50%) of their nonhuman primates with feeding enrichment... Fruit was distributed at all facilities, nuts and seeds at 95%, vegetables at 91%, manufactured treats at 73%, and other items at 64% of facilities. Manipulanda: All facilities employed manipulable objects. Of the categories of manipulanda provided as response choices, the items used most frequently were mirrors (100%), balls (95%), synthetic chew toys (86%), and hanging toys (86%). Rattles were provided at 68% of the facilities, wood at 59%, and bells at 18%. Devices: Ninety-one percent of facilities reported the use of enrichment devices. Of the devices offered as response choices, the most common were puzzle tube feeders (77% of facilities) and Astroturf foraging boards (77%), followed by puzzle balls (59%), fleece boards (36%) and other devices (36%). Structural Enrichment: Most facilities reported providing structural enrichment to all of their animals. All facilities reported the use pf perches, 73% swings, 59% used barrels, 50% bedding/nesting materials, 36% exercise cages or playrooms. With respect to social housing, in the 1994 survey 38% of indoor-housed macaque species were housed socially. In the current survey, among these species, 44% of the individuals in cages wee housed socially. This comparison indicates that the use of social housing for caged primates has not expanded as substantially as many applied behavioral scientists would have hoped... Social housing options are more often limited by research protocol constraints than are other forms of enrichment.Since the practice of single housing is a major risk factor for the development of abnormal behavior, the continued prevalence of single housing perpetuates the need for intervention.