Science / Medicine : Pediatrics for a Precious Panda : Scientists Are Ready to Step Right In When Ling-Ling Gives Birth
Red lights flicker over the sleeping panda as remote-control cameras hum in the corners of a temperature-controlled cage. An around-the-clock watch has been posted, and scientists are standing by with the latest in veterinary technology, including an antibody-rich solution refined from panda blood.
Officials at the National Zoo are leaving nothing to chance as they prepare for the birth, expected any day now, of an extremely rare panda cub.
Frustrated zoo officials have watched Ling-Ling, the female of the zoo’s celebrated giant panda couple, give birth three times in recent years to cubs that either were born dead or died shortly after birth. This time they are waging an all-out offensive of human and technological intervention to ensure that this cub has a good chance of surviving.
By learning from past failures and devising new ways to combat the bacterial infections that have plagued those pregnancies, zoo scientists feel they have a better chance than ever of successfully nurturing a cub that would be the first reared in the United States and only the seventh outside China.
“We know more now than we’ve ever known,” said zoo collections manager Lisa Stevens, who like all of her colleagues is hoping for success but wary of predicting it. “We’re constantly gaining knowledge every time there’s a birth.”
Most important, Ling-Ling’s past pregnancies have convinced veterinarians that they cannot rely on her to provide the newborn cub with the antibodies it needs to fight off deadly infections. This time, in an extraordinary step, they plan to anesthetize Ling-Ling soon after birth, take her cub away and then feed it a special antibody solution before returning it to its mother’s care.
The plan carries some risk because of the delicacy of the mother-infant bond in pandas. However, the scientists are optimistic that if they act quickly and cautiously, the result could be a first-time healthy baby and a new procedure that could be used worldwide to increase the dwindling panda population.
“There is a very high potential to significantly add to the wild population and repopulate some areas if we can solve some of these problems (of infections),” said zoo Director Michael H. Robinson, adding that fewer than 1,000 pandas are believed to exist in the animal’s natural habitat in southern China’s mountainous rain forests.
Ling-Ling’s new pregnancy is the latest chapter in a long-running love story that has periodically captured the imaginations of Washingtonians and panda buffs across the country since the prized pair arrived in the United States in 1972 as gifts of the Chinese government.
The two are the only members of their species in a permanent zoo collection in the United States, and they have spawned an enormous outpouring of American public interest. The panda couple remain the biggest attraction at the National Zoo, which draws about 4 million visitors a year.
“People think they’re just big teddy bears that you’d want to go up and give a big hug,” said zoo spokeswoman Margie Gibson.
However, dwelling in separate glass enclosures in an exhibit building and roaming a small grassy compound, the pandas have often not shown much affection for each other. The only pandas successfully bred outside China have been in Mexico City, with four offspring, and Tokyo and Madrid with one each.
The National Zoo first tried to mate Ling, as she is known by staff members, and her male companion, Hsing-Hsing, in 1976, but had no success for seven years. Tireless efforts were foiled by an assortment of snafus: first, Hsing (pronounced Shing) had trouble finding an “effective breeding posture”; then, a male panda loaned by the London Zoo as a substitute suitor did little but spar with Ling; attempts at artificial insemination yielded only a false pregnancy.
Ling finally mated successfully with Hsing in 1983 and twice more over the next four years. But all four cubs--one pregnancy yielded twins--died, three of them of infections (one of those was stillborn).
Autopsies on two cubs that were born apparently healthy showed that Ling was for unknown reasons unable to supply the infants with the high dose of antibodies normally present in panda mothers’ milk.
After Ling lost a 4-day-old cub last June, vets decided that should the 19-year-old female conceive again, they would step in to compensate for this shortcoming in the cub’s first hours of life.
The cub “can pick up bacteria from almost anywhere--from its mother’s skin, from her breast . . . from the cage floor,” Robinson said. “We have to have some shield against those, and that’s why we have come up with this new plan.”
Within six hours after the birth, zoo vets plan to shoot an anesthetic dart into Ling and, as she falls over, run into the cage and snatch the cub out of her arms to avoid the possibility of Ling crushing her offspring. They will then give the cub a physical exam, clean it and feed it the all-important antibody solution through a stomach tube. As Ling begins to awaken, the cub will be returned to her, after having been dabbed with panda secretions to mask the scent of human contact.
The antibody substance was prepared recently by a Maryland laboratory using blood from Hsing. Antibodies in his blood were separated out in a centrifuge and turned into a highly concentrated serum.
Zoo officials say they have used a similar process for several years on other animals that have had trouble transmitting antibodies. But they have never used such a concentrated solution, and they have never used the procedure on such a priceless specimen.
“We’re just applying a new state-of-the-art technology to help us do a better job with the concept,” said Mitchell Bush, the zoo’s chief veterinarian.
The antibody serum is only part of the extraordinary effort the zoo is making to assist nature. In order to reduce the amount of bacteria in Ling’s cage, the zoo removed rocks normally provided for Ling to sit on and filled in cracks in the floor where germs could flourish.
Shifts of volunteers have been monitoring Ling’s behavior 24 hours a day since July 5 by closed-circuit television, and vets have prepared a sound system to amplify the cub’s noises--the most important means of communication between panda mother and infant--in the event Ling has trouble hearing them.
Should there be a second chance to give the cub more antibody solution--if, for example, Ling puts the baby down and moves to the other side of the cage for a moment--vets have prepared an injectable form of the substance to use for a quick booster.
But no matter how much the zoo intervenes at first to protect the cub’s health, zoo officials insist, the ultimate responsibility is Ling’s to mother the baby as only a panda could.
