Ailurus fulgens, commonly known as the red or lesser panda, is a small mammal found in the Himalayan region of China. Known colloquially as a ‘living fossil’, the red panda is of particular interest to evolutionary scientists due to its early divergence from ancestor species. This early divergence has made the red panda difficult to place phylogenetically, in addition to its conflicting diet and morphological features.
There are two subspecies of red panda; Ailurus fulgens fulgens and Ailurus fulgens styani, with the former being the most populous, and the latter being known as the Chinese or Styan’s red panda. Both are usually referred to informally as just ‘red panda’.
The red panda is a small, stocky animal with a superficial physical similarity to the domestic cat, which led to its Latin name (literally ‘shining cat’). It has red-brown fur, the limbs being a darker brown. The red panda has distinctive white facial markings; a white muzzle and cheeks separated by brown ‘tear’ markings and white ears. The red panda also has a long, bushy tail barred with brown and white stripes, culminating in a black tip. They have sensory vibrissae on their cheeks, similar to cats. The subspecies A.f. styani is purported to be larger and darker than A.f. fulgens, however, some variation can be observed in both subspecies; individuals may be any shade from dark brown to yellow-brown. Red pandas generally weigh about 5 kilograms. They do not have any discernible sexual dimorphism.
The red panda also possesses a ‘false thumb’, a small bone in the forelimb which aids in gripping. This is generally accepted as being a particular specialization to the red panda’s herbivorous diet, allowing it to handle bamboo shoots and leaves despite its lack of opposable digits. Interestingly, the red panda shares this physical feature with the giant panda, though the two species are not closely related. (The giant panda is an ursid; the red panda’s phylogeny will be discussed later.)
Red pandas are found exclusively in the Himalayas. More specifically, their distribution ranges from Nepal though Tibet into Sichuan and Yunnan Provinces in The People’s Republic of China. A.f. styani is the only subspecies found in Sichuan; A.f. fulgens is more common in the westernmost areas of the species’ range. The range is more or less contiguous, with an isolated area in Nepal which is separate from the rest of the population. Claims have been made of red panda populations existing in other nearby areas, such as Gansu Province, but these have been proved to be erroneous. Fossil records have shown that the red panda’s range was larger than it is today, with fossils of the red panda being found in other provinces of China such as Guizhou Province. Generally, they are restricted to areas of the Himalayas with temperate forests.
The red panda’s favoured food source is bamboo; specifically, the young, tender shoots and leaves of the plant. Bamboo may represent 54% to 100% of the red panda’s diet; one particular species, known locally as jhapra, seems to be preferred by the animal. However, the red panda has been known to supplement this diet with fruits, flower blossoms, berries, eggs, and even small birds. Such a low quality diet is supported by physical adaptations; the red panda has a low metabolic rate, low skin temperature and thick fur which help to conserve internal temperature.
Red pandas tend to be nocturnal, though in the wild they have been proven to be active during both day and night, due to their low-energy diet. They tend to be solitary animals, only interacting with other members of their species during breeding seasons. They are territorial, and mark the boundaries of their territories with scent and urine. Red pandas may defend their territory with a visual display of arching their back and tail, and emitting a hissing or huffing noise.
Red pandas have a gestation period of about 134 days; cubs are thus born around early spring. Litters in captivity have a mean of two cubs, while lower birth rates are experienced in the wild. Infants weigh approximately 120 g at birth. Like cats, red panda cubs are born with closed eyes and ears and tend to be grayish rather than the distinctive red-brown of an adult. Adult colouration generally appears at two months of age.
The cubs stay with their mother until the next breeding season, when the mother becomes aggressive towards her last litter. Male participation in cub rearing is rare in the wild, mostly due to the red panda’s solitary nature. Red pandas reach adult size at about 12 months of age, but do not become sexually mature until they are 18 months old. The maximum lifespan of a red panda in captivity is 14 years.
Although it shares diet and habitat with the giant panda, and the oddity of being generally herbivorous despite being classified in the Carnivora order, the red panda has been more or less excluded from the Ursidae family, due to its lack of physical similarity. It is generally accepted that the red panda diverged from a common ancestor with the giant panda too long ago to be counted as closely related, and as such their dietary similarity is considered an example of convergent evolution.
The red panda’s pelt is valuable locally for clothing and hats. A hat made from red panda fur is considered to be a lucky charm for newlyweds, and thus such items are in some demand and are sold illegally on the black market. This indicates a degree of hunting and poaching which are devastating in an already small population. Being classified as category II indicates that it is illegal to hunt the species without permission from the appropriate authorities; yet black market trade and poaching continue to threaten the species. Deforestation in unprotected areas of the panda’s habitat also threatens its survival, not only by destroying food and living areas, but by isolating small populations and increasing genetic instability and susceptibility to natural disaster. Captive breeding programs are in place in many parts of the world, including Australia, and are intended to ensure the species’ continuity.
References:
Antón, M., Salesa, M.J., Pastor, J.F., Peigné, S. & Morales, J. (2006) Implications of the functional anatomy of the hand and forearm of Ailurus fulgens (Carnivora, Ailuridae) for the evolution of the ‘false-thumb’ in pandas. Journal of Anatomy 209, 757-764
Choudhury, A. (2001) An overview of the status and conservation of the red panda Ailurus fulgens in India, with reference to its global status. Oryx 35 (3), 250-259
Flynn, J.J., Nedbal, M.A., Dragoo, J.W. & Honeycutt, R.L. (2000) Whence the red panda? Molecular Phylogenetics and Evolution 17(2), 190-199
Gittleman, J.L. (1994) Are the pandas successful specialists or evolutionary failures? BioScience 44 (7), 456-464
Glatston, A.R. (1994) Status survey and conservation action plan for procyonids and ailurids: the red panda, olingos, coatis, raccoons, and their relatives. International Union for Conservation of Nature and Natural Resources, Gland, Switzerland.
Ledje, C. & Arnason, U. (1996) Phylogenetic relationships within caniform carnivores based on analyses of the mitochondrial 12S rRNA gene. Journal of Molecular Evolution 43, 641-649
Mayr, E. (1986) Uncertainty in science: is the giant panda a bear or a raccoon? Nature 323, 769-771
O’Brien, S.J., Nash, W.G., Wildt, D.E., Bush, M.E. & Benveniste, R.E. (1985) A molecular solution to the riddle of the giant panda’s phylogeny. Nature 317, 140-144
Roberts, M.S. & Gittleman, J.L. (1984) Ailurus fulgens. Mammalian Species 222, 1-8
Sato, J.J., Wolsan, M., Minami, S., Hosoda, T., Sinaga, M.H., Hiyama, K. Yamaguchi, Y. & Suzuki, H. (2009) Deciphering and dating the red panda’s ancestry and early adaptive radiation of Musteloidea. Molecular Phylogenetics and Evolution 53, 907-922
Su, B., Fu, Y., Wang, Y., Jin, L. & Chakraborty, R. (2001) Genetic diversity and population history of the red panda (Ailurus fulgens) as inferred from mitochondrial DNA sequence variations. Molecular Biology and Evolution 5, 1070-1076
Tedford, R.H., & Gustafson, E.P. (1977) First North American record of the extinct panda Parailurus. Nature 265, 621-623
Wei, F., Feng, Z., Wang, Z. & Hu, J. (1999) Current distribution, status and conservation of wild red pandas Ailurus fulgens in China. Biological Conservation 89, 285-291
Wei, F., Feng, Z., Wang, Z. & Hu, J. (2000) Habitat use and separation between the giant panda and the red panda. Journal of Mammalogy 81(2), 448-455
Wei, F., Wang, Z., Feng, Z., Li, M. & Zhou, A. (2000) Seasonal energy utilization in bamboo by the red panda (Ailurus fulgens). Zoo Biology 19, 27-33
Yonzon, P.B. & Hunter, M.L. (1991) Conservation of the red panda (Ailurus fulgens). Biological Conservation 57, 1-11
Zhang, Y. & Ryder, O.A. (1993) Mitochondrial DNA sequence evolution in the Arctoidea. Proceedings of the National Academy of Sciences USA 90, 9557-9561