Tuskless elephants evolving thanks to poachers
More male Asian elephants in China will be born without tusks because poaching of tusked elephants is reducing the gene pool, a recent study predicts.
Research by Zhang Li, an associate professor of zoology with the college of life sciences at Beijing Normal University, discovered that the gene for tusklessness is spreading among the endangered species in its habitat in Yunnan Province of Southwest China.
The gene, which exists in Asian elephants at a normal ratio of 2 to 5 per cent, has increased to 5 per cent to 10 per cent in China among males of the species, according to Zhang's research.
"This decrease in the number of elephants born with tusks shows the poaching pressure for ivory on the animal," said Zhang, who has led his research group at the reserve in the Xishuangbanna Dai Autonomous Prefecture since 1999, where two-thirds of China's Asian elephants live.
Their research involves about 100 Asian elephants living in the reserve area, of which only 20 are adult males.
"We found two of 20 do not have tusks," Zhang said.
Only male elephants have tusks, which are said to be a symbol of masculinity and a weapon to fight for territory. However, due to poaching for ivory, the elephants' pride has become a death sentence.
"The larger tusks the male elephant has, the more likely it will be shot by poachers," Zhang said. "Therefore, the ones without tusks survive, preserving the tuskless gene in the species.
"It is not the result of natural evolution. Rather, it is a reluctant choice made in the face of a gun."
The depletion of the gene pool was explored in Uganda by Eve Abe, who commented that a gene for tusklessness is spreading throughout the elephant population in the country's Queen Elizabeth National Park, which experienced heavy poaching in the 1970s and '80s.
However, Zhang's assertion about the tusklessness gene among the Asian elephants due to poaching remains in doubt among some international academicians.
"This is, of course, a possibility, but till now there is no clear genetic proof that it can occur," said Vivek Menon, executive director of the Wildlife Trust of India, a non-profit conservation organization that fights to prevent the destruction of India's wildlife.
"The elephants will evolve towards higher security and evolve as tuskless. But we cannot say that it is already happening."
So far, there are between 45,000 and 50,000 Asian elephants in 13 countries, including China and India. China only has about 250.
Poaching is an alarming threat to the remaining few, in addition to the problems of loss of habitat as a result of the invasion of human activity.
Because of the rampant killing of male elephants for tusks, the female-to-male ratio has changed from the ideal 2:1 to 4:1 in China and 100:1 in India.
The uneven ratio is attributed to the dramatic reduction in the fertility of the species and the depletion of its gene pool, Zhang added.
Some adolescent elephants are killed before they breed.
Last year in China, four Asian elephants were found shot dead.
International trade in ivory was illegalized in 1989 in a treaty administered by the Convention of International Trade in Endangered Species Fauna and Flora (CITES). Some 160 member nations, including China, have signed the treaty banning the trade of products from endangered animals.
(China Daily 07/16/2005 page1)
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