All the government chimps are headed to Chimp Haven, a sanctuary in Keithville, La., where they will have a full social life and room to roam outdoors.
Some critics say the process has been unnecessarily slow, but both Chimp Haven and the N.I.H. say transfers are moving more quickly now. The sanctuary has accepted 14 chimps in the past two months and is expecting more before the end of the year.
Chimp Haven, with a staff of 50, more than 200 chimps and a 30-year history, has had a lot of experience caring for retired chimps. They are kept in mixed groups of various sizes and their social interactions monitored.
To prevent breeding new chimps that would have to spend their lives in captivity, Chimp Haven gives all the males vasectomies.
But “vasectomies do fail,” said Raven Jackson-Jewett, the attending veterinarian at the sanctuary. “Conan was the one that taught us that.”
Conan had the procedure but somehow fathered three youngsters anyway, including Tracy, now 10 and a favorite of visitors. Dr. Jackson-Jewett said that because of Conan, Chimp Haven had learned that chimp vasectomies fail more often than those in humans.
The staff changed its technique, re-vasectomized about 75 chimps with the new method, and hasn’t had a pregnancy since.
The sanctuary also has learned to care for frail chimps. Many animals from labs have been infected with H.I.V. and hepatitis for vaccine experiments, and some have diabetes (not related to experiments).
They are often old: Some arrive near 50 years of age, and the lifespan of chimps in captivity runs from 50 to 60 years. Occasionally chimps are deemed too old even to handle the stress of being sent to the sanctuary.
The sanctuaries hope eventually to put themselves out of business. If all goes as planned, in another 50 years or so, there will be no more lab retirees.
Chimps will still be in zoos and, as the laws now stand, private owners could still breed them. But since the demand for their use in research is now zero, that is unlikely to happen on a large scale.
Most privately owned laboratory chimpanzees are also headed for retirement centers. New Iberia has shipped 22 animals to Project Chimps, where Bo and his cohort now live, but still has nearly 200.
The Project Chimps facility, which formerly housed gorillas, is still being renovated for chimps. They will get to play in eight acres of walled-in open space, with trees, a stream and an open meadow — once the walls are fixed. (Unlike gorillas, chimps are agile climbers.)
Those left at New Iberia aren’t isolated. They live in groups in large, dome-shaped outdoor cages. The domes have a bit less than a 1,000 square feet of floor space.
Although chimps in research were once housed in smaller cages, and in isolation for experiments, practices have changed; labs and sanctuaries have recognized that it is cruel to house chimps alone.
The only other private chimps still at research institutions include 46 owned by the Yerkes National Primate Research Center at Emory University in Atlanta, and one at the University of Georgia. Yerkes is looking for retirement facilities for its chimps and has sent seven to the Chattanooga Zoo.
Yerkes also sent eight chimpanzees to an unaccredited zoo in England, prompting an outcry from animal welfare advocates in this country and in Europe. The move prompted a lawsuit, because the Fish and Wildlife Service approved it even though advocates insisted there were better options in the United States.
Yerkes said that the English zoo was well equipped and enlisted comment from Dr. Goodall, who said she had visited the facility and supported the move.