FRONT ROYAL, Va. — The five red panda cubs in large boxlike cribs at the Smithsonian Conservation Biology Institute are bottle-fed, sleepy and wobbly on their legs. They have bandit masks and thick, rich fur, and they make soft squealing noises and something called a huff-quack, which sounds like . . . a huff-quack.
They are surrounded by silly grins as they are lifted out and fed — wide, involuntary and irrepressible face-splitting smiles. No one — scientist, reporter or photographer — is immune to the baby panda smile reflex.
The scientific literature reflects the red panda's appeal. Frédéric Cuvier, who published the first Western scientific description of the animal in 1825, deemed it "quite the most handsome mammal in existence." One of the foremost modern authorities, Angela Glatston, in a book she edited about red panda biology, described the animal as "flamboyantly clad in chestnut, chocolate and cream," and called it "a creature of great beauty and charm."
Although it is hard to capture in words exactly what red pandas are like, Anna Kendrick, the actress who starred in both Pitch Perfect movies, among others, came as close as anyone after she had been panda-struck at Prospect Park Zoo in Brooklyn.
On Late Night With Seth Meyers," she said: "They're like a fox and a raccoon and a bear and a dog and a cat. They're like every adorable animal in one animal."
Darwin could not have said it better.
And yet, even though they inspire delight, and have a presence in movies (the master in Kung Fu Panda), and on the Internet (in lots of videos and as the avatar of @darth, a popular Twitter persona), they are far less well known and understood than that other panda, the giant black and white one.
And they are in trouble. The International Union for the Conservation of Nature, which assesses the status of wild populations of animals, estimates that about 10,000 live in the wild, in two subspecies, all on mountain slopes in a narrow band running from western China to Nepal. Deforestation and disease threaten them now, and climate change looms.
Glatston, who recently retired from the Rotterdam Zoo, runs the global species management program for red pandas for the World Association of Zoos and Aquariums. She said that zoos around the world, outside China, kept about 500 red pandas, which they breed to try to maintain a population as a stopgap against threats to wild pandas. The captive-bred pandas could, so the theory goes, be reintroduced into the wild, if necessary.
And those are the pandas that researchers study, by and large, because it is so hard to observe them in the wild. "They are secretive animals," said Elizabeth Freeman, a conservation biologist at George Mason University and a research associate at the Smithsonian institute.
Researchers hope new insights into the behavior, health and reproductive biology of the red pandas will help the zoo programs and tell them something about wild pandas. "We just want to answer very basic questions," Freeman said.
Red pandas are about 2 feet long when they are grown, not counting their bushy, banded tail. They are built for cold weather: Even the bottoms of their feet are furred.
They are listed as vulnerable, by the IUCN, although some scientists are pushing to have them classified as endangered, the next step up.
They live in mixed forests with an undergrowth of bamboo, at an altitude of 4,600 to 15,000 feet, Freeman said — a limited ecological niche. Like giant pandas, they feed primarily on bamboo, although they apparently supplement that with eggs, small birds and insects.
Their closest relatives are probably raccoons, but their ancestors and raccoon ancestors split into separate evolutionary lineages about 26 million years ago. And they are not closely related to giant pandas. The giant panda is in the bear family, and the red panda is the only species in the family Ailuridae.
If the red panda were to become extinct, Glatston said, that would be, at least taxonomically, "like losing the whole cat family, from lions to domestic cats." The Latin name for the species is Ailurus fulgens — or fire-colored cat. One common name is firefox, which was borrowed for the popular Internet browser.
Although they are sometimes called the "lesser panda," a label red panda researchers disdain, they were discovered by Westerners decades before the discovery in 1869 of the giant panda. They are unquestionably the first panda, and, Glatston argues, "In fact, the giant panda is a bear, and this is the only panda."
The Smithsonian institute is home to the largest colony of red pandas in North America — 17, including this season's six babies, although the number fluctuates as some young pandas move to zoos elsewhere. The adults live in high-domed cages, with nesting boxes that can be cooled during hot weather.
Researchers are collaborating on studies of the pandas' health and behavior with a facility in Chengdu, China, which has about 100 of the animals, and also houses giant pandas.
One of the problems in maintaining populations is reproduction in captivity. Only about half the young survive, and researchers say that is probably because mothers do not provide enough milk or care for the young properly. No one knows whether similar problems exist in the wild, Freeman said.
The institute has five cubs this year being hand-raised and one being cared for by its mother. The human-raised cubs are bottle-fed and housed in large cribs divided by screens, because they can unwittingly harm each other.
Three of the five came from a mother who had terminal cancer. She was kept alive through the pregnancy because her offspring were considered important for genetic diversity, but then she was euthanized.
The two other cubs came from a mother who has had trouble raising cubs in the past. Being raised by humans is not ideal for any animal, but it is sometimes necessary. And filling the role of a panda mother means more than just holding a bottle.
The cubs do not urinate or defecate on their own. Those urges are prompted by their mothers' licking their abdomen and anus. Human caretakers have to rub them to get the same response, and are clearly delighted when the cubs produce.
Ken Lang, a supervisory biologist at the Smithsonian facility, who tends the cubs with Jessica Kordell, an animal keeper and graduate student at George Mason who is studying with Freeman, said the hand-raised cubs did well.
"They go on to breed," he said. "They lead successful lives." They are much slower than dogs or cats to develop, he said, taking about four months to function on their own.
The advances in red panda science are incremental, and are answering questions that can seem surprisingly basic.
At the Cincinnati Zoo, home to two breeding pairs of adult red pandas, one older female and two cubs, Erin Curry is a reproductive physiologist who works primarily with polar bears. This year, she used a combination of ultrasound and hormone levels to predict due dates for two red pandas. Their gestation time was about 70 days.
The ultrasound was used to detect fluid levels in the uterus, not the panda fetus. Freeman points out that the pandas frequently have false pregnancies and that often, "We can't even confirm that they're pregnant." When red pandas are born, they weigh about 31/2 ounces and fit in a cupped palm.
Freeman and her colleague Copper Aitken-Palmer, chief veterinarian at the Smithsonian Conservation Biology Institute, are working in China to do a survey of the panda's health and study their behavior.
Aitken-Palmer, who also worked on giant pandas, said preliminary results showed that dental disease was an issue as well as fractured tails — perhaps because of aggression among the animals — and some unexplained changes in levels of vitamins and minerals.
"It's hard to say what's normal," she said.
This spring, Freeman presented findings at the Animal Behavior Society meeting in Anchorage, Alaska, that confirmed that red pandas preferred to be on their own. Social housing is not necessarily a good thing, as it is with many other animals.
Red pandas in the wild face threats from expanding human populations, Glatston said, in the form of habitat loss and disease, primarily distemper from domestic dogs, to which they are very susceptible.
There are some conservation efforts in China, but the one Western conservation organization devoted specifically to the animal is the Red Panda Network, a small nonprofit based in Kathmandu, Nepal, and San Francisco that works to protect the population in Nepal. Glatston is on the board.
With a total of about 700 members, a staff of six and a number of zoos that donate money, the network is working on several fronts. Nancy Whelan, the director of development, said the group had set up a forest guardian program that pays 54 local people to monitor red panda populations and potential threats.
They have joined forces with village committees that are instrumental in managing what are called community forests. They are working to make more fuel-efficient stoves available to combat deforestation.
And, in concert with local organizations, the network is supporting the creation of a protected forest in a wildlife corridor in eastern Nepal, called the Panchthar-Ilam-Taplejung Red Panda Protected Forest.
"Twenty-five percent of Nepal's red panda population is moving in that corridor," Whelan said.
Some of the habitat loss, however, may be beyond local control.
"I think down the road what may actually do them in is climate change," Freeman said. "Because they are in such a small niche in the Himalayas, and as climate change warms that area and moves that population higher in elevation, they're going to lose habitat probably faster than they can accommodate to climate change."
She added, "I see them as being a critical indicator species for the health of the Himalayan ecosystem, probably more so than giant pandas."
The effort to understand and to protect red pandas is now at the point at which work on giant pandas was 50 years ago, Aitken-Palmer said.
"It feels very much like we're at the beginning," she said. "In some ways, it's really exciting. In other ways, a little daunting."