FEATURE - Mexico zoo anxiously tries breeding giant pandas
Date: 01-May-03
Country: MEXICO
Author: Anahi Rama
Is she sleeping more? Is she eating differently? Are her breasts swollen?
Xin Xin, one of three female giant pandas who live in Mexico City's Chapultepec Zoo, was born there during a highly successful programme to breed the endangered species in the 1980s. She was artificially inseminated a few weeks ago with sperm from Chinese panda Ling-Ling.
Ling-Ling has travelled to Mexico from his home in Japan's Ueno zoo every year for the past three years, staying from January to April each time in the hope that he will impregnate one of the Mexico City pandas.
But Ling-Ling has yet to hit it off with any of his potential mates and so far yearly attempts at artificial insemination have also failed.
"Panda reproduction is very difficult. A lot of factors come into play. It's a lot of work," said Fernando Gual, the veterinarian who runs the 17-hectare (42-acre) Chapultepec Zoo, in the centre of teeming Mexico City.
Female pandas go into heat only once a year, for only 72 hours, and can be picky in choosing a mate. But the zoo is committed to trying again and again to reproduce pandas here.
Some 800 to 1,000 giant pandas survive in the wild in southwestern China. They are threatened by the loss of their habitat even though China has intensified its conservation efforts in recent years.
Another 150 live in captivity, only about 15 outside China and North Korea. The bamboo-eating animals, which weigh 130 kilos (290 lbs) when full grown, are the centre of attention in any zoo lucky enough to have them.
China donated two giant pandas to Mexico in 1975 and it became the first country outside China to achieve reproduction in captivity. Of eight pandas born in Mexico in the 1980s, five survived.
HOPE AND FRUSTRATION
After that success, the new breeding programme with Mexico's three panda females, is considered the great hope for panda breeding worldwide. But it has been frustrating so far.
A small army of specialists and caretakers are involved in the project, including scientists from the San Diego Zoo, where a panda was born in captivity in 1999.
The experts at Chapultepec Zoo have gone through a battery of tests and have ruled out fertility problems on either side of the equation.
They believe the problem comes down to compatibility between Beijing-born born Ling-Ling and the three Mexican-born female pandas Xin Xin, Shuan Shuan and Xiu Hua.
"The male's sperm is good. And we don't see any physical impediment for reproduction," Gual said.
The ideal breeding situation for pandas is to have several males so that the women can choose, but that would be expensive for the programme, which is financed in part by the San Diego Zoo.
Adult pandas generally lead solitary lives in the wild, but researchers believe Ling-ling could have formed some sort of long-time attachment to female Tong Tong, who died in Japan in 2000 after they had lived together for many years.
This year before Ling-Ling left for Japan on April 26, the two younger Mexican pandas, Shuan Shuan and Xin Xin, were inseminated for a third time with his sperm. Scientists said they would have to wait for several months to know whether there would be any luck this time around.
"It's not like humans where you can do a urine exam and detect pregnancy. With pandas there is nothing to do but wait," said Gual.
Ling-Ling, who may soon be too old to father cubs, is scheduled to return to Chapultepec in 2004 and in 2005, unless the scientists decide to change the programme and fly one of the Mexican pandas to Japan to see if a change of scenery will help them get in the mood.