By The Numbers

NIH chimps program retired

David Weinberg Jun 27, 2013

The National Institutes of Health just announced that it’s going to drastically reduce the number of chimpanzees it keeps in captivity for medical research.

The plan is to move all but 50 of the 451 chimps to sanctuaries where they will be required to have at least 1,000 square feet of living space. Not exactly paradise for an animal that will walk for miles in the wild–but a vast improvement form their current life of confienment. There are still about 500 chimps owned by private research facilities.

One reason that the NIH is making the move — it is really expensive to keep these chimps. 

In fact, many private pharmaceutical companies have already stopped using chimps. There are cheaper alternatives and several countries have banned the use of chimps for medical research.


On January 22, 2013, the NIH Council of Councils received a report with recommendations for how chimps should be retired. It included these 10 recommenditons for” ethologically appropriate physical and social environments”

  1. Chimpanzees must have the opportunity to live in sufficiently large, complex, multi-male, multi-female social groupings, ideally consisting of at least 7 individuals. Unless dictated by clearly documented medical or social circumstances, no chimpanzee should be required to live alone for extended periods of time. Pairs, trios, and even small groups of 4 to 6 individuals do not provide the social complexity required to meet the social needs of this cognitively advanced species.
  2. The density of the primary living space of chimpanzees should be at least 1,000 ft2 (93 m2) per individual.
  3. Chimpanzees must be housed in environments that provide outdoor access year round. They should have access to natural substrates, such as grass, dirt, and mulch, to enhance environmental complexity.
  4. Chimpanzees should have the opportunity to climb at least 20 ft vertically. Moreover, their environment must provide enough climbing opportunities and space to allow all members of larger groups to travel, feed, and rest in elevated spaces.
  5. Progressive and ethologically appropriate management of chimpanzees must include provision of foraging opportunities and of diets that are varied, nutritious, and challenging to obtain and process.
  6. Chimpanzees must be provided with materials to construct new nests on a daily basis.
  7. The environmental enrichment program developed for chimpanzees must provide relevant opportunities for choice and self-determination.
  8. Chimpanzee management staff must include experienced and trained behaviorists, animal trainers, and enrichment specialists to foster positive human– animal relationships and provide cognitive stimulation. Given the importance of trainer/animal ratios in maintaining trained behaviors, a chimpanzee population of 50 should have at least 2 dedicated staff members with this type of expertise. Positive reinforcement training is the only acceptable method of modifying behaviors to facilitate animal care and fulfillment of management needs.
  9. All personnel working with chimpanzees must receive training in core institutional values promoting psychological and behavioral well-being of chimpanzees in their care.
  10. Chimpanzee records must document detailed individual animal social, physical, behavioral, and psychological requirements and these requirements should be used to design appropriate individualized chimpanzee management in the captive research environment.

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