To keep their interest and encourage natural behaviors, animals in research facilities are often offered enrichment devices: objects to gnaw on, nesting materials that allow them to custom build their shelters, "food puzzles" to forage, and various toys to keep them occupied during the long hours cooped up in cages. For highly intelligent primates, mental stimulation and access to outlets for natural exuberance are especially important.
When it comes to monkeys, one way to keep things from getting too dry is to add a little water. According to the Animal Welfare Institute’s Laboratory Animal Advisor, Viktor Reinhardt, "Providing monkeys with ‘swimming pools’ during the hot summer months is probably one of the most attractive environmental enrichments for them. Macaques and baboons are good swimmers and divers, but just simply playing with water can fascinate them for extended periods of time."
In a recent discussion on AWI’s Lab Animal Refinement & Enrichment Forum (LAREF), Reinhardt asked forum participants to offer anecdotes on water play for primates. Several caregivers wrote back to share their stories. Among the comments:
"At my last facility we used kiddie pools with our outdoor housed [cynomolgus] and rhesus [macaques]. The cynos spent a lot more time in/around the pools. It was really cool to see the juvenile cynos actually swimming in the pools (underwater with eyes open)! Some of the juvie rhesus would get in the water but not too many (more ‘in and out’ quickly)."
"We’ve observed the monkeys enjoying ‘running water’ as much as swimming! Sometimes we’ll take an old hose, turn it on & slide it into their enclosure. Sometimes with certain monkeys… we’ll actually give them the hose and let them ‘aim & spray’ & play, but they WILL trash the hose in short order. Other times we keep the hose on the outside of the enclosure and just let the water run in. They LOVE it!"
"Our senior NHP [non-human primate] technician has come up with a square stainless steel water pan insert that is approximately two inches in height that fits inside the entire area of the view port and can be filled with water. It is by no means large enough for our NHPs to fit their bodies in the tub, but gives them access to playing with water.... The NHPs that have used the prototype have spent a lot of time splashing their hands and arms in the water, cleaning their fruit/veggies and their toys. I have found it to be very rewarding to observe. The other monks watch intently for hours as well."
It is incumbent upon research facilities to address not only the physical needs of the animals, but their emotional needs, as well. When caregivers provide species-adequate enrichment devices - in this case, water play for primates - they help stave off boredom and contribute to the animals' overall well-being.