Thanks to science, there are more baby pandas China's panda experts improved breeding pandas in captivity 12 years ago, Chengdu zoo keeper had only 20 pandas, now center has more than 100 animals Challenge is reintroducing captive pandas back into the wild Chengdu, China (CNN) -- The researcher dressed in blue plastic smock, slippers and gloves is having a tough time getting his work done. Every time Zhang Zhen sets up his camera on a tripod in an effort to document the behavior of one of the panda cubs scattered on a grassy hillside, one particularly frisky baby panda comes wobbling towards him, interrupting his shoot. "Mumu!" he yells in frustration, as the four-month old cub rears up on her hind legs, lunging towards him. He picks Mumu up and deposits her at the opposite end of the enclosure. I'm not sure why she's been all over me like this. I think she's excited today," Zhang says. Mumu is the oldest of fourteen baby pandas that were born last summer here at the Research Base of Giant Panda Breeding in Chengdu, China. China's panda experts have improved the science of breeding and raising members of this endangered species in captivity. The proof of their success is in the baby panda enclosure, where visitors can watch as the newest generation of pandas takes turns napping, playing and exploring their outdoor habitat. The fuzzy young cubs are still shaky on their feet, and often trip and roll down the enclosure's slight incline. While two cubs wrestle, another tries to climb a tree and then tumbles onto its back, slowly performing a backwards somersault, much to the amusement of onlookers. "There are new breakthroughs, so that's why the panda population has continued to increase," said Deng Tao, the chief zoo keeper at the Chengdu base. When Deng first began working at the base 12 years ago, he said there were only 20 pandas here. Today, the center is responsible for more than 100 animals. Deng recently returned from the Atlanta Zoo, where he spent months assisting with the birth and care of twin cubs who were born there last July. "Now we have new technologies that can very accurately identify when a panda is ovulating and do artificial insemination during a precise point in the [reproductive] cycle," Deng explained. On its website, the Atlanta Zoo credited Deng and his colleagues in Chengdu with developing a technique using incubators and taking turns rotating twin cubs with the mother to better ensure the newborns' chance of survival. "Before when a panda had twins, the mother panda could only take care of one cub so we have resolved the issue of having twin pandas and helping them to integrate," Deng said. The next big challenge facing China's panda keepers involves reintroducing captive animals back to the wild. "We have made a training base to return pandas to the wild," Deng explained. Once they are mature and able to forage for food and hide from danger, then we will release some pandas. Wildlife conservation groups say China's effort to save the giant panda from extinction is a rare success story. According to the World Wildlife Fund, as of 1988 there were only around 1,000 pandas left living in the wild. In 2004, that number was estimated to have grown to 1,600 wild pandas. More recent panda census statistics are not yet available. The government put the resources [into conservation]. They've actually set up some mountains just as a habitat for the panda," said May Mei, the chief representative in China for the conservation group WildAid. China has lavished resources on the conservation of the giant panda- rather than on some other indigenous endangered species- in large part because the animal is such an important national symbol. "They are a treasure for people in China," Mei said. The breeding center in Chengdu is also something of a panda theme park. Excerpts from the animated DreamWorks film "Kung Fu Panda" play on a giant screen at the entrance to the facility, which receives more than a million visitors a year. Inside, tourists travel in panda mobiles, decorated with the cartoon movie's main character, Po the Panda. In addition to stuffed animal pandas, souvenir shops offer a variety of hats, ear muffs, and even fuzzy nunchucks decorated with the panda's distinctive black-and-white panda patterns. Visitors walk along paths, gazing and taking photos of pandas in large outdoor pens. The animals seem to completely ignore humans. In one pen, a 25-year-old male named Shi-shi lies on his back, gorging himself on bamboo which he holds in his front paw with the help of what trainers call the panda's "pseudo-thumb." Other adults seem to spend much of their time fast asleep in their enclosures. But the big lumbering animals clearly have charisma. "They're cute man!" says Chris Delbene, a 21-year-old university student from Orego who is studying Chinese in Beijing. They live a great lifestyle, play all day, eat, sleep. CNN's Steven Jiang contributed to this report.