(CNN) -- China's giant pandas are believed to be safe after Monday's earthquake, but concern is growing over how they will get their next meals.



The giant pandas' primary food source is bamboo.



Authorities confirmed Tuesday that captive animals in two of China's major panda reserves were alive, according to Xinhua, China's official news agency.



The Wolong Giant Panda Reserve Center in southwest Sichuan province is home to about 86 giant pandas, who were reported safe Tuesday.



Staff and critters at neighboring Chengdu Panda Breeding and Research Center were also reported safe, according to a spokesperson for the Atlanta Zoo, which has two pandas on loan from the wildlife reserve.



Concern arose in the international wildlife community over damage to the animals' habitat, as authorities continued assessing the scope of damage in the Sichuan province.



The mountainous, densely wooded region is the natural habitat for most of the 1,200 giant pandas living in the wild, making it an obvious location for research bases like Wolong and Chengdu. Giant pandas roam the forest in "open cages" that are meant to provide them with a safe, natural environment that will prepare them for release.



With the safety of the pandas confirmed, the animals' caregivers are left to determine how resources like food and medical supplies will reach the bases, which contain breeding facilities and triage centers.



Bamboo, the pandas' primary source of food, is a major agricultural product in the region, but whether it can be supplied to the pandas despite infrastructure damage is open to question.



"Wolong is hard to access under normal conditions, so the heavy road damage makes it even harder," said Kerry Zobor, spokesperson for the World Wildlife Fund.



Zobor said WWF had confirmed the safety of staff based in Beijing, but had not received word on the conditions in Wolong. She said the WWF was also concerned about members who had been touring the country when the earthquake struck. So far, the group has not been located.



Scientists in the United States are hopeful that Chinese researchers will adapt to the situation facing them.



David Wildt with the Smithsonian's National Zoological Park in Washington says that scientists in Wolong have overcome threats to the giant panda population before.



In the late 1990s, the captive giant panda population was in decline, with more animals dying than were born, Wildt said.



Thanks to a collaborative effort with American scientists, the Wolong staff was able to reverse the trend.



"Our Chinese colleagues are very perceptive when it comes to addressing problems," said Wildt, who has visited Wolong many times as part of the Smithsonian's affiliation with the research base. "Because of their efforts, the population is on the rise today."



Wildt said that Chinese scientists have also addressed the issue of alternative food sources before.



"Artificial diets in the form of protein biscuits have been created for giant pandas. They're not a complete substitute, but they meet the needs of a basic high-fiber diet," said Wildt, who has worked with two pandas that the Smithsonian has on loan from Wolong.



"Right now, we're mostly concerned about the staff. If the staff is fine, then the animals will be fine," Wildt said.
Where are they keeping the giant pandas? What were the growing concerns about? Report: Chinese authorities confirm that captive giant pandas are safe Scientist: Alternative foods exist in the event of depleted bamboo stocks What do the authorities confirm are safe? What do pandas eat? What type of food exists in event of depleted bamboo stocks? Who confirmed that the giant pandas are safe?
southwest Sichuan province how they will get their next meals. after Monday's earthquake, protein biscuits giant pandas primary food source is bamboo. "Artificial diets in the form of protein biscuits Authorities
question: Where are they keeping the giant pandas?, answer: southwest Sichuan province | question: What were the growing concerns about?, answer: how they will get their next meals. | question: Report: Chinese authorities confirm that captive giant pandas are safe, answer: after Monday's earthquake, | question: Scientist: Alternative foods exist in the event of depleted bamboo stocks, answer: protein biscuits | question: What do the authorities confirm are safe?, answer: giant pandas | question: What do pandas eat?, answer: primary food source is bamboo. | question: What type of food exists in event of depleted bamboo stocks?, answer: "Artificial diets in the form of protein biscuits | question: Who confirmed that the giant pandas are safe?, answer: Authorities