[monkeywire] Zoos put chimps on birth control to keep breeds pure

Carrie McLaren carrie at stayfreemagazine.org
Fri Aug 9 18:00:27 EDT 2002

Asahi News Service
August 1, 2002 Thursday


Zoos are putting chimpanzees on the pill to stop them from giving 
birth to mixed breed chimpanzees.

Chimpanzees are classified into four subspecies according to their 
habitats-East African, West African, Central African and Nigerian. 
They are not migratory animals and do not interbreed under natural 
circumstances. But until recently, Japanese zoos and research 
facilities have let their chimps breed randomly, unaware of what 
subspecies their chimpanzees belong to. When they tried to obtain 
chimps from their counterparts in Western nations, they were turned 
down for that reason. Western facilities began distinguishing 
chimpanzee subspecies about a decade ago and refuse to do business 
with zoos and research centers that do not follow suit.

To remedy the situation, a group of experts including Koichiro 
Yoshihara, a chimpanzee breeder at Tama Zoological Park in Tokyo and 
Kenichi Shinoda, an associate professor of physical anthropology at 
Saga Medical School, examined the DNA of chimpanzees at 56 facilities 

A total sample of 373 chimpanzees consisted of 243 West African, four 
Central African, 13 East African chimpanzees and 65 that were not 
clearly identified. The rest-48 chimpanzees-were crossbreeds, 
including some that were mixtures of three subspecies.
While some researchers say crossbreeding is not harmful unless the 
animals return to the wild, Yoshihara disagrees.

"We need to control the population of crossbreeds, and at the same 
time prevent incest from occurring. But that would reduce the chances 
of acceptable mating, which may cause the steadily increasing 
chimpanzee population in Japan to decline drastically," he said.

The experts recommended that each zoo counter crossbreeding by 
keeping only one subspecies and devising its breeding plan. 
Birth-control was recommended for crossbred chimps, as well as 
separate habitats for each subspecies to prevent interbreeding.
At Tama Zoological Garden, seven out of the zoo's 18 chimpanzees are 
mixed-breed. Nine are West African and two are Central African.

Kenta, an alpha male chimpanzee that came from another zoo, turned 
out to be a mix between Central and East African. He already 
underwent a vasectomy, according to a zoo official.

Four female chimps, including Peko, 40, and her daughter Koko, 17, 
have also been identified as crossbreeds, who are now on 
birth-control pills.

Carrie McLaren
Editor, Stay Free!

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