Kitty the chimpanzee

Kitty, a 51-year-old chimpanzee once kept in captivity as a breeder for a biomedical research facility, died Friday in a Texas sanctuary. (Humane Society of the United States / December 6, 2013)

Kitty, a female chimpanzee that gave birth to many offspring used in laboratory experiments, has died in a Texas animal sanctuary, the Humane Society of the United States announced Friday.

Believed to have been born some 51 years ago, Kitty had been held in captivity at the former Coulston Foundation biomedical research facility in Alamagordo, N.M., where she was used as a breeder.

Kitty was transferred in 1997 to the Cleveland Amory Black Beauty Ranch, in Murchison, Texas, which is operated by the Fund for Animals in partnership with the Humane Society. There, Kitty became a companion to the famed Nim Chimpsky, subject of a controversial experiment that attempted to show primates could learn language.

While at the New Mexico facility, Kitty gave birth to 14 infants, including two sets of twins, and all but four were taken from her in their infancy, according to Wayne Pacelle, president and chief executive of the Humane Society of the United States, who announced the death on his blog Friday.

Among Kitty's offspring were Dar es Salaam, one of five chimpanzees taught American Sign Language at Central Washington University. Dar died of cardiac arrest last year at the university's Chimpanzee and Human Communication Institute.

The use of primates in medical experiments once was widespread, but has gradually fallen out of favor, in part due to a wave of animal rights activism and new regulations.

The U.S. Fish and Wildlife Service earlier this year proposed extending its endangered species protections to captive chimpanzees, which could limit their role as human surrogates in research. The close cousins to humans have been used to test vaccines against infectious diseases and develop treatments for cancers and autoimmune diseases.

The National Institutes of Health in June announced it would retire 310 of the 360 chimpanzees it kept for research. The move came after lengthy public review of the agency's policies and practices that included thousands of comments from the public, largely supporting retirement of the primates.

Research scientists, some of whom have been the target of protest, argue that without chimpanzees, major advancements in human health would be thwarted. Nonetheless, many have resorted to using rodents or other animals that can be bred and genetically altered to mimic human-like biological conditions.

A 2001 study in the journal PLOS ONE found that 58% of chimps retired from biomedical research showed signs of depression, while 44% had signs of post-traumatic stress disorder. Both conditions were virtually absent in wild chimpanzees. The study was led by researchers from Physicians Committee for Responsible Medicine, which is opposed to animal research.

Kitty lived to what is considered an advanced age for captive chimps, which seldom live past 40 years. The oldest captive chimpanzee, with an estimated age of 75, is Little Mama at Lion Country Safari in Loxahatchee, Fla.

[Updated Dec. 6, 5:45 p.m.:

"It was hard losing her," Laura Maloney, chief operating officer of the Humane Society of the United States, said of Kitty.

Staff at the Texas facility allowed the other resident chimpanzees to see and touch Kitty's body before it was removed in preparation for a necropsy, to be performed at Chimp Haven in Keithville, La., Maloney added.

"It's a way for them to come to terms," she said.

Kitty had suffered some neurological problems in the past weeks, a possible sign of a stroke, which is a relatively common cause of death among captive chimpanzees, Maloney said.]