(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.

uthorities 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, spokeswoman for the World Wildlife Fund.

Zobor said the WWF had confirmed the safety of staff members 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.

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 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."

"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.