Physical Description
Red pandas can be easily identified by their unique ruddy coat color, which acts like camouflage within the canopy of fir trees where branches are covered with clumps of reddish-brown moss and white lichens.

They have large, round heads and short snouts with big, pointed ears. Their faces are white with reddish-brown “tear” marks that extend from the eyes to the corner of the mouth. These markings could have evolved to help keep the sun out of their eyes. Their tails are marked with alternating red and buff rings.

Red pandas have a soft, dense woolly undercoat covered by long, coarse guard hairs. Long, bushy tails help these arboreal animals maintain balance and protect them from harsh cold and winds. Dense fur completely covers their feet which have five, widely separated toes and semi-retractable claws.

Red pandas scent-mark territories using anal glands and urine, as well as scent glands located between their footpads. These scent glands on the bottom of red pandas’ feet exude a colorless liquid that is odorless to humans. The red panda tests odors using the underside of its tongue, which has a cone-like structure for collecting liquid and bringing it close to a gland inside its mouth. It is the only carnivore with this adaptation.

Red pandas are skilled climbers, using trees for shelter, to escape predators and to sunbathe in the winter. Their ankles are extremely flexible, and the fibula and tibia are attached in such a way as to allow the fibula to rotate about its axis. These features make it possible for red pandas to adeptly climb headfirst down tree trunks.

In contrast with other carnivores their size, red pandas have extremely robust dentition. They also have a simple carnivore stomach, despite their predominantly leaf-based diet. Red pandas share the giant panda’s pseudo-thumb, a modified wrist bone used to grasp bamboo when feeding.

Red pandas are the only living member of the Ailuridae family, and their taxonomic position has long been a subject of scientific debate. They were first described as members of the raccoon family (Procyonidae) — a controversial classification — in 1825, because of ecological characteristics and morphological similarities of the head, dentition and ringed tail. Later, due to some agreements in DNA, they were assigned to the bear family (Ursidae).

Most recent genetic research, however, places red pandas in their own, independent family: Ailuridae. Molecular phylogenetic studies show that red pandas are an ancient species in the order Carnivora (superfamily Musteloidea) and are probably most closely related to the group that includes skunks, raccoons and weasels.

While originally thought to be two subspecies, new genetic studies suggest that there are two distinct species of red panda: Ailurus fulgens fulgens and Ailurus fulgens styani (also known as Ailurus fulgens refulgens). The latter tends to be larger and deeper red in color than the former.

Size
Adult red pandas typically weigh between 8 and 17 pounds (3.6 and 7.7 kilograms) and are 22 to 24.6 inches (56 to 62.5 centimeters) long, plus a tail of 14.6 to 18.6 inches (37 to 47.2 centimeters).

Native Habitat
Red pandas live in high-altitude, temperate forests with bamboo understories in the Himalayas and other high mountains. They range from northern Myanmar (Burma) to the west Sichuan and Yunnan Provinces of China. They are also found in suitable habitat in Nepal, India and Tibet. Ailurus fulgens fulgens lives predominantly in Nepal and can also be found in India and Bhutan. Ailurus fulgens styani (or Ailurus fulgens refulgens) is primarily found in China and Myanmar.

Communication
Red pandas are generally quiet, but subtle vocalizations—such as squeals, twitters and huff-quacks—can be heard at close proximity. They may also hiss or grunt, and young cubs use a whistle, or high-pitched bleat, to signal distress. Red pandas will climb trees and rocks to escape predators, such as leopards and jackals.

Food/Eating Habits
Bamboo constitutes about 95% of the red panda's diet. Unlike giant pandas that feed on nearly every above-ground portion of bamboo (including the culm, or woody stem), red pandas feed selectively on the most nutritious leaf tips and, when available, tender shoots.

Like giant pandas, red pandas grasp plant stems using their forepaws and shear selected leaves off with their mouths. Because red pandas are obligate bamboo eaters, they are on a tight energy budget for much of the year. They may also forage for roots, succulent grasses, fruits, insects and grubs, and are known to occasionally kill and eat birds and small mammals.

At the Smithsonian's National Zoo, red pandas eat bamboo, bamboo shoots (when in season) and leafeater biscuits. They are receive enrichment treats, such as apples, grapes, bananas, blueberries and other produce.

Social Structure
Red pandas are solitary except during the breeding season. In human care, most breeding pairs live together year-round. In the wild, the home range of one animal is about 1 square mile.

Reproduction and Development
In the Northern Hemisphere, red pandas breed from January through March. In the Southern Hemisphere, breeding season extends from June through August. The rapid change in photoperiod, or day length, after the winter solstice initiates this breeding season.

Mating occurs on the ground, and gestation appears to include a period of delayed implantation, which may be as short as 93 days or as long as 156 days. Reproduction expends a great deal of energy, so it is believed that a long gestation period may be the result of a slow metabolic rate. Late spring births also coincide with the emergence of the most tender and digestible bamboo shoots and leaves.

Females create a nest in tree holes, hollow stumps, tree roots or bamboo thickets and line the nest with moss, leaves and other soft plant material. Litters typically consist of two cubs born between May and July in the Northern Hemisphere.

Red pandas are born completely covered in fur to protect them from the cold environment. Newborns of the species Ailurus fulgens fulgens weigh 3-4 ounces (about 90-110 grams). The offspring stay with the mother for about one year, which is about when they are full-grown. Red pandas reach sexual maturity at around 18 months of age.

Sleep Habits
In human care, red pandas can be active at any time of day but are primarily crepuscular, or most active at dawn and dusk. On average, they spend about 45 percent of the day awake and tend to be more active in cooler weather, especially during the winter mating season.

In significantly cold temperatures, red pandas can become dormant, lowering their metabolic rate and raising it every few hours as they wake up to look for food.

This adaptation allows red pandas to spend nearly as little energy as sloths, which is very beneficial considering the low nutrition content of their diet. They also exhibit temperature-regulating behaviors, such as curling into a tight ball to conserve body heat and energy expenditure in the cold. Conversely, when temperatures are warm, red pandas stretch out on branches and pant to lower their body temperature.

Lifespan
Red pandas may live as long as 23 years. They show symptoms of age at around 12 to 14 years old. While females do not breed after age 12, males continue to be reproductively capable.