The Prevention of Environmentally Caused Injury In Captive Chimpanzees (Pan troglodytes) at the Primate Foundation of Arizona (PFA)

James Murphy
Primate Foundation of Arizona
P.O. Box 20027
Mesa, AZ 85277-0027

Appropriate maintenance of captive chimpanzees (Pan troglodytes) must include the challenge of providing them with a living environment that is functional, stimulating, and safe. At the Primate Foundation of Arizona (PFA), the safety and physical and mental well-being of the animals is our top priority. This priority is reflected in the design of the animal cages, the enrichment materials provided, and our standard operating procedures. 

The indoor cages at PFA are built in place. They are constructed of half inch galvanized steel woven mesh across the front and between cages. The openings in the mesh are large enough to allow climbing without risk of fingers or toes becoming trapped. The back walls, ceilings, and floors are reinforced concrete. The cages are furnished with horizontal benches and both vertical and horizontal climbing poles. Water containers and feeders are made of stainless steel and can be easily removed from the cages for cleaning. All surfaces, including the walls (which are impervious to moisture), are easily cleaned and sanitized to prevent growth and spread of pathogens. Swabs for bacterial cultures are taken quarterly from randomly selected cages and feeders to monitor the effectiveness of our sanitation program. Hydraulic guillotine doors connect the indoor and outdoor cages. The doors move slowly and are in view of the operator so the door can be immediately stopped should an animal suddenly enter the doorway. 

Animal escapes are equally as dangerous for the animals as for humans in the area. An escaped animal may be injured by other animals or by physical hazards, such as electrical wires, outside of the cage areas. To prevent escapes at PFA, all cage doors are equipped with two padlocks and a sliding bolt. In the event that one lock fails or is not locked properly, there is always a back-up. Yet, if an animal does escape, all cage areas inside and out are equipped with locking safety doors that can be closed to minimize the range of an escaped animal or to serve as a safety corridor for humans.

The Sonoran Desert location of the facility poses a few unique problems. Because of desert denizens, such as rattlesnakes, scorpions, etc., all outdoor cages must be checked thoroughly twice daily prior to allowing the chimpanzees to have access. The straw bales for bedding are stored in an open-air, covered barn. Before bringing the straw into the animal building, each bale is opened and inspected. Any foreign matter found is removed. 

Enrichment items are thoroughly examined for potential hazards. Ropes used for brachiating are at least one inch in diameter and are always anchored at both ends. Enough slack is left in the rope so that it can swing and move freely but not enough to form a loop which could trap or ensnare an animal. Plastic barrels that previously contained food or other non-toxic materials are utilized several ways. By cutting an opening in one side, a barrel becomes a one chimp "igloo" hiding place. Others are cut in half and hung by ropes to make a swing. All suspended, swinging items are hung with at least four pieces of rope. The ropes are attached diagonally to walls or other structures, and pulled tightly enough so that they cannot be looped. If cable instead of rope is used for hanging devices, the cut ends are thoroughly filed and then covered with a short piece of rubber hose. The entire cable is then covered with canvas fire hose. Chains are never used because of the possibility of an animal getting a finger stuck in a link. Heavy objects, like extra large boomer balls, are not used because they may be thrown, causing injury to a young animal. 

Maintaining chimpanzees in captivity is a tremendous responsibility. Dangers that may be unique to their captive situation must be avoided. Institutions that house chimpanzees must carefully assess their cage areas, care staff procedures, and enrichment items for hazards that may cause injury to the animals. This assessment will become second nature over time, and as new procedures and environmental changes are proposed, they will be examined with more insight as to whether they are truly in the best interest of the chimpanzees. 
 



Reprinted with permission of the Editor of The Newsletter.