The efforts of Chinese zoologists to avoid inbreeding and ensure
heredity diversity of captive Siberian tigers are paying off,
according to a scientist from the world's largest artificial
breeding base for the rare species.
Scientists at the Hengdaohezi Feline Raising Center in Harbin,
capital of Heilongjiang Province in northeast China, have
conducted DNA tests on 200 of the 700-plus tigers in the park in an
attempt to introduce selectivity into the breeding process.
"We have seen signs of genetic degeneration in the past due to
inbreeding. We used to have at least one or two cubs with
deformities among the newborns every year," said chief zoologist
Liu Dan.
"Encouragingly, we haven't found any tiger cub born with birth
defects in the last two years," Liu said. "This shows that DNA
testing is conducive to preventing genetic degeneration of the
Siberian tigers."
Siberian tigers, among the world's 10 most endangered species,
mostly live in northeast China and the Far East area of Russia. Of
the 400 estimated to live in the wild, only 10 to 17 live in
northeast China.
The Siberian tiger is listed as "endangered" on the Red List of
Threatened Species of the World Conservation Union and is also
listed on the Convention on the International Trade in Endangered
Species (CITES) Appendix I which prohibits the trade of live tigers
or tiger parts.
To protect the rare tigers from extinction, China established
the Harbin base in 1986. The base now has more than 700 Siberian
tigers in captivity, including over 100 born this year, compared
with only eight when it was set up. The population is expected to
double by 2010.
The expansion of the captive Siberian tiger population excites
zoologists at the center but also brings challenges.
"A female tiger usually mates with several male tigers so it's
hard to know the identity of the real father of the tiger cub," Liu
said.
Experts believe inbreeding of the tigers is partly blamed for
the apparent genetic degeneration.
"With DNA testing, we can sort out the bloodlines of all the
tigers and prevent inbreeding," Liu said.
The DNA test project was kicked off in June 2001 with support
from the State Forestry Administration (SFA).
SFA has allocated more than 1 million yuan (US$127,748) for the
project so far and the center has raised an additional 300,000
yuan. A significant proportion of the funds will be used to
establish a DNA bank and the development of computer software which
will calculate the optimum breeding match for tigers based on the
DNA test results.
The long-term plan of the Harbin center is to train and release
620 Siberian tigers into the wild.
(Xinhua News Agency December 17, 2006)
