Seven monkeys from the colony at the California National Primate Research Center at UC Davis died last month due to overheating from a faulty room heater. An eighth monkey was treated successfully.

Campus animal-care technicians making routine checks discovered the animals about 8:30 a.m. Aug. 21 and alerted primate center veterinarians. The animals were part of the center's breeding colony and were not involved in research projects.

"We regret and are saddened by the deaths of these animals," said primate center director Dallas Hyde. "Our staff is dedicated to the compassionate care of every animal living in our program, and will be working to ensure this cannot happen again."

The eight animals, all adult female cynomolgous monkeys from 5 to 8 years old, were housed in the same room at an Animal Resources Service facility on campus, separate from the primate center site.

A failure in the room's ventilation system overnight apparently caused heated air to be blown into the room. The temperature in the room was about 115 degrees when the animals were found

The ARS facility provides overflow housing for the primate center colony. As a precaution, 32 other monkeys housed at the ARS facility have now been moved back into temporary space at the primate center, which has 24-hour environmental monitoring of all rooms.

Staff found no signs of a break-in or suspicious activity at the scene. The cause of the heating fault is being investigated.

Construction projects to expand indoor and outdoor animal housing are currently in progress at the primate center. One of eight national primate centers funded by the National Institutes of Health, the center houses approximately 4,700 monkeys for studies by scientists working in the western United States. Most of the monkeys are rhesus macaques, with smaller numbers of cynomolgous and South American titi monkeys.

The monkeys are essential for studies that are providing insight into the nature and treatment of devastating human illnesses, including asthma, autism, Alzheimer's disease, and HIV/AIDS and other infectious diseases.