Opal the chimpanzee is 34 years old and lives in an enclosure at the Southwest National Primate Research Center in San Antonio.

Her medical file describes her as “light complexion, freckled, thin, big ears that stick out, white beard, green eyes." The file also states that she's endured 19 liver biopsies and 219 chemical immobilizations, according to the Humane Society of the United States' review of federal inspection reports. She's also infected with hepatitis B.

"Her records show a history of plucking out her hair and eating it, a behavior associated with stress and trauma," a Humane Society report states.

Opal is one of 20 chimps owned by the National Institutes of Health that were transferred to Southwest from the Alamogordo Primate Facility in New Mexico, where hundreds of chimps had been retired from biomedical research. Opal and her peers were called out of retirement in 2010 and were once again made available for testing.

And now, in the wake of the U.S. Fish and Wildlife Service's decision to declare captive chimpanzees endangered, animal welfare groups are calling for Opal and 19 other federally owned chimps at Southwest to be permanently retired.

The Alamogordo chimps had originally been used for research by the U.S. Air Force, but in 1970, the Air Force leased them to private labs. One of those labs was run by toxicologist Frederick Coulston, head of the Coulston Foundation. At his peak, Coulston had control of roughly 600 chimps.

In 1993, three chimps — Robert, James, and Raymond — overheated and died when their enclosures reached 150 degrees, according to the Physicians Committee for Responsible Medicine's review of federal records. The USDA cited the Coulston Foundation for the deaths of those three, plus two more who died in 1997, then again in 1998, when Terrance, Holly, and Muffin died "from a known side effect of an experimental drug," according to the Physicians Committee.

In 1999, the Coulston Foundation settled with the USDA and agreed to transfer ownership of 300 chimps to the agency by January 2002.

But a USDA inspection report shows that Opal was still in Coulston's custody in April 2002. She was one of 14 chimps Coulston kept in single cages. The inspectors wanted to find out why that was.

"There is no approved justification based on medical, study, or compatibility reasons for keeping these animals in single cages," the inspectors concluded. They found that the 14 chimps were medically and psychologically distressed. Their muscles had atrophied and their tendons contracted. They lost weight and had a vitamin D deficiency because they never saw the sun. They over-groomed and had patches of hairless skin. They showed signs of "depression or aggressive behavior due to lack of social interaction and stimulation."

Coulston surrendered the 14 chimps to the NIH, and they were free from "invasive experimentation" until 2010, according to the Physicians Committee for Responsible Medicine.

That's when the NIH began transferring chimps to Southwest, a facility that's been cited for violating the Animal Welfare Act, and where veterinarians once attempted a necropsy on a baboon they thought was dead but wasn't. Southwest gets paid by the NIH per diem, per chimp, whether or not they're used for research. According to Southwest's grant application to house the chimps, the daily rate would be adjusted after every 20 deaths.

Southwest's notion of chimps was perhaps best summed up in 2011, by then-director John VandeBerg, who told an NBC interviewer, "I think of the chimpanzees in the same way that I think of a library. There are told books in the library that will never be used this year or next year. Many of them might never be used again. But we don't know which ones will be needed tomorrow, next year, or the year after."

A year after the Alamogordo chimps were called out of retirement, the Institute of Medicine concluded that most chimp research was "unnecessary." The NIH retired most of its chimps and transferred them to sanctuaries.

But Opal and 19 others remained at Southwest. Their biggest allies include the Humane Society of the United States and Animal Protection of New Mexico. They want the chimps transferred to Chimp Haven, a sanctuary in Louisiana comprising 200 acres of forest.

"When more chimps get into sanctuary, they have a chance to experience life as a chimpanzee, rather than an invasive test subject," Laura Bonar, program director for Animal Protection of New Mexico, wrote in a June column for the Albuquerque Journal.

The HSUS also notes that it's more expensive to warehouse chimps at a research facility, like Southwest, than at a sanctuary.

A Southwest spokeswoman told The Houston Press that the chimps aren't currently being used in research, and NIH officials stated in 2013 that its grant to Southwest, for the housing of the chimps, did not include plans for future research. So it's a little unclear why the chimps are there, instead of Chimp Haven.

Two former Alamogordo chimps at Southwest that we wrote about in 2012 aren't listed in Southwest's most recent inventory of government-owned chimps, according to Kathleen Conlee, the Humane Society of the United States' vice president of animal research issues. She says that it's probably because they're dead.

Those chimps were Ken, 32 at the time of our story, and 30-year-old Katrina. Katrina spent most of her time in a New York laboratory, where she endured biopsies of her liver, rectum, lymph nodes, and cervix. In 1994, after coming out of a ketamine daze, she mutilated her thumb. Between June 2001 and March 2002, when she was first retired, she lost one-third of her body weight.

Ken underwent serial blood sampling from the time he was 12 hours old until his first retirement in 1996. He put in time at the Centers for Disease Control, where he was infected with hepatitis A from human feces, and with HIV. By the time he was called out of retirement in 2010, his health had deteriorated to the point where veterinarians inserted a "do not resuscitate" order into his medical file.

It appears it's too late for Ken and Katrina to make it to Chimp Haven. But it's not too late for Opal, or the others.

Chimps generally live 30-40 years in the wild, but can live 50-60 years in captivity. That's a painful amount of time for intelligent, social animals to be in the custody of people who think of them as books on a shelf. They should go somewhere where they can be chimps. The Southwest 20 should be allowed to live the second half of their lives in peace.