PANDA: EVOLUTION, CHARACTERISTICS, DANGER OF EXTINCTION, HABITAT - BIOLOGY - 2025

The panda or giant panda (Ailuropoda melanoleuca) is a placental mammal belonging to the order Carnivora. The physical appearance of this animal is unique, its figure is rounded with a black and white coloring of its fur. In his body they stand out, in a black tone, his extremities, ears, tail and a band on his back. His eyes, although they are small, look imposing as they are surrounded by a black circle.

The panda bear is located in central Asia. Due to the reduction of its habitat, its population has decreased considerably, so it is currently within the category of vulnerable species, according to the categorization carried out by the International Union for Conservation of Nature.

Source: pixabay.com

These animals move slowly, with somewhat awkward movements. They rest for long hours during the day, because in this way they save energy. They are generally active at dusk or at night.

Although the panda devours bamboo stems and leaves almost insatiably, its digestive system is similar to that of a carnivorous mammal. However, your body has undergone some adaptations to facilitate the digestion of vegetables.

Predators

Due to their large size and the habitat where they are found, adult pandas have almost no natural predators. However, the cubs are completely defenseless until they reach one year of age. This makes them easy prey for jackals and leopards.

Humans represent one of the biggest threats to the giant panda. They are hunted illegally and sold for a high price on the black market. Despite the existence of laws that severely punish this act, man continues to do so, putting the small population of this species at risk.

Black and white coloring

Although the appearance of some mammals includes gray and brown colorations, the panda is an exception. Its fur has a strange pattern of black spots on the ears and eyes, on a white face.

The neck and torso are white, but its front and rear legs and shoulders are black. This pattern is almost non-existent in other land mammals.

To know the evolutionary and functional importance of this coat, studies have been carried out, under a comparative phylogenetic approach, between various carnivores and the subspecies of the order Carnivora.

The results showed that the panda's coloration fulfills various functions. First, the white areas of the body such as the nape, face, flank and belly, are adapted to be a camouflage against a snowy background.

The back and extremities, black in color, are adapted for crypsis in the shade. The spots on the head are not camouflages, but are used for communication. Black ears would be associated with the intention to send a message of ferocity.

The huge black circles around the eyes are useful in individual recognition and as a threat to other animals.

Evolution

The origin of the Ursidae family dates back to 20 million years ago, in the Miocene. The fossil record of Ursavus elemensis, found in Subtropical Europe, identifies it as a bear about the size of a dog.

It developed characteristics of a bear, in the shape of its teeth. In this sense, the carnassial teeth were reduced and the molars had expanded the surface of the bite.

Molecular analyzes show that the giant panda forked in the early Miocene from the oldest line of the Ursidae. This occurred as a consequence of a very fast radiation event.

Due to the scarcity of fossil records corresponding to the Miocene, the origin of the giant panda has been under constant investigation.

Generally, the Asian ursid Ailurarctos, located in China, is identified as the oldest species of the Ailuropodinae. However, some current studies link the extinct genus Agriarctos, which lived in Europe during the Miocene, with the Ailuropodinae family.

Agriarctos gaali shows primitive adaptations to durophagia, just as Ailuropoda melanoleuca possesses it. This makes it considered the primitive member of the giant panda lineage.

-Recent research

Miomaci panonnicum

In the town of Rudabányam, in Hungary, fossil remains belonging to a new species of the Ursidae, Miomaci panonnicum nov. gen. This new species has elements in common with the Indarctos, within the Ailuropodinae subfamily.

The study of dental wear indicates that it fed on resistant plants and that it lived on the shores of lakes, where monocots were abundant. These are considered ecological similarities to the giant panda.

Kretzoiarctos gen. Nov.

A new extinct primitive genus, belonging to the giant panda lineage, was found in the Vallès-Penedès basin, Spain. It lived in the Middle Miocene and represents the oldest specimen of the entire Ailuropodinae subfamily, which includes the Ailuropodini and Indarctini.

Because the Kretzoiarctos is known only in the Vallès-Penedès and Calatayud-Daroca basins, in the Iberian Peninsula, research supports the position that the Ailuropoda melanoleuca had an origin on the European continent.

General characteristics

Organs of the digestive system

The esophagus is covered by a resistant corneal tissue, which protects this delicate structure from possible injuries caused by the passage of bamboo chips.

The stomach is protected with thick muscular linings, which protect it from the pointed parts into which the bamboo has divided when it is cut and chewed.

Size and weight

At the time of birth, the calf can weigh between 100 to 200 grams, measuring between 15 and 17 centimeters. Once adults, males weigh about 150 kilograms and measure 150 centimeters. On the other hand, females reach a lower weight, around 125 kilograms.

Fur

The fur of the giant panda is thick. Its color is creamy white with large black spots on the limbs, nose, shoulders, and ears. Around the eyes it has black spots that distinguish the species.

The denseness of their hair means that these animals can maintain a regulated body temperature.

Extremities

Its legs have five fingers and a sixth finger or thumb. This extra finger is actually a pad that covers a radial sesamoid bone that has been modified.

This opposable thumb is highly practical for the animal, as it allows it to hold the bamboo stems and leaves, allowing it to handle them with precision and dexterity.

Their front legs are more muscular, strong and flexible than their hind legs, as they are used to climb trees. In the hind limbs, his heels have no pads. Unlike bears, the giant panda cannot stand up on its two hind legs and walk upright.

Skeleton

The skeleton of Ailuropoda melanoleuca is similar to that of bears, except that the cranial region is slightly larger. This is because it must withstand the increase in muscles associated with chewing.

Skull and jaw

In the giant panda these bone structures include some modifications that allow it to adapt to a strictly herbivorous diet. The temporal fossa is expanded. The zygomatic arch is enlarged, increasing the attachment surface for the masseter, zygomatic and mandibular muscles.

The lateral expansion of this arch widens the temporal fossa and limits the horizontal movement of the lower jaw. The large, strong jaw muscles extend to the top of the head.

Face

Its head is round with a snout that is flatter than that of bears. It has short, erect and rounded ears. Their eyes have elongated pupils, like most nocturnal animals. This allows them better vision at night.

Premolar and molar teeth are wide and flat. Their crests and cusps are extensive, allowing them to more easily grind the bamboo stem.

Language

The tongue has some adaptations for a plant-based diet, especially bamboo stalks. In addition to this, this muscle must conform to the highly specialized way of eating.

It has four types of papillae: conical, fenced, filiform, and fungiform. These are found distributed on the back, in the ventral area and on the anterior surface of the tongue.

The central zone does not have any type of taste bud. This is because the animal drags the food towards the teeth, rubbing it from one side to the other, trying to remove the outer layer of the bamboo.

Baculum

This bone is found in the penis of the male giant panda. In the vast majority of bears this complementary structure is straight and in a forward direction. In the giant panda it is directed backwards and is shaped like an "S".

Why is the panda bear in danger of extinction?

Distribution of the panda population

Since 1986, the International Union for Conservation of Nature has paid special attention to the notable decline in the Ailuropoda melanoleuca population.

In later years, the problem not only continued, it got worse every day. The panda was considered endangered by the IUCN, however the world environmental organization changed its status to vulnerable in 2016.

This is because the great efforts for its conservation are beginning to bear fruit and the population is increasing.

Causes

There are many causes that have led this animal to be in danger of extinction. One of them is the destruction of their natural habitat.

In ancient times, the panda was distributed throughout southern China, to northern Beijing and southeast Asia. At present, the serious ecological alteration of its habitat has limited it to live in western China, in the provinces of Gansu, Shaanxi and Sichuan.

Natural habitats have been cut down, eliminating entire hectares of bamboo forests, a staple food in the panda's diet. In addition to this, the low birth rate and the high mortality of the offspring make the population of this animal increase at a fairly slow rate.

Another downside is that in captivity, giant pandas have a hard time reproducing, largely due to the fact that they are extremely shy animals.

Its biological niche is frequently shared with black bears and musk deer. When the human sets traps to hunt these animals, the panda can end up hurt by them.

Poachers also contribute to the disappearance of this species, when they kill the panda to sell its skin. This hunt, despite being illegal and legally penalized with large sums of money and jail, is still being carried out.

Actions for the conservation of the species

Since 1990, China has implemented environmental policies in favor of the conservation of this species, considering the giant panda as an animal of great national value. The natural reserve system has been expanded from fourteen, which existed before, to more than sixty sites.

These reserve programs prohibit the felling of forests, which contributes to a decrease in land degradation. In addition, farmers in the area are being incentivized to plant trees on slopes in order to reduce erosion.

In addition to this, they have implemented several cooperation agreements between countries, in order to join efforts in training on captive breeding, including reproduction techniques.

Since 1981 the trade in panda skins has been illegal. In 1988 the Chinese government enacted the Life Protection Law, prohibiting its hunting and granting it the status of a nationally protected species.

All these efforts are bearing fruit, as the population of these animals is increasing significantly. Future strategies are oriented towards cooperative work between science and environmental and environmental policies, in the application of new pro conservation plans.

Taxonomy

Animal Kingdom.

Subkingdom Bilateria.

Infra-kingdom Deuterostomy.

Chordate Phylum.

Vertebrate Subfilum.

Tetrapoda superclass.

Mammal class.

Subclass Theria.

Infraclass Eutheria.

Order Carnivora.

Suborder Caniformia.

Family Ursidae.

Genus Ailuropoda

Species Ailuropoda melanoleuca

Source: pixabay.com redesigned by Johanna Caraballo

Habitat and distribution

Although the giant panda was previously found north of Beijing and southeast China, today the largest populations are found in the Minshan, Qionglai and Qinling mountain ranges.

In a smaller population number and in an isolated way, they remain in the mountains of Liangshan, Xiaoxiangling and Daxiangling, in China. These contractions in habitat are due to the expansion of human urbanism and the conversion of bamboo forest areas to agriculturally cultivated areas.

Whereas these animals previously occupied forests below 1,000 meters of altitude, the current populations of Ailuropoda melanoleuca are restricted to mountain range regions, which are separated by flatter landscapes and valleys.

The mountains where they are found are covered with humid coniferous forests, where bamboo grows widely. These temperate ecosystems are one of the richest in animal and plant species on the planet. Their height can range from 1200 to 3400 m asl

One of the main characteristics is that this environment does not have significant annual climatic variations, therefore the weather conditions remain relatively stable all year round.

New tracking technologies

Technological innovations are being used in order to obtain detailed and highly reliable information on the migratory behavior of the panda. One of them is the Global Positioning System (GPS).

This high-resolution telemetry system allowed data to be reviewed and added to previous findings, based on VHF. It is a band of the electromagnetic spectrum, which works in a frequency range between 30 MHz and 300 MHz.

GPS tracking of Ailuropoda melanoleuca documents, in addition to a greater range, the skewed dispersal of females and their temporary migrations during the mating stage.

The data showed some individual movements within the same habitat and on a large scale between different regions, probably associated with foraging. Pandas frequently return to their previous habitat, which may be related to a developed spatial memory.

There are other remote sensing techniques, including the Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Spatial Reflection and Thermal Emission Radiometer (ASTER).

These data contribute significantly to the knowledge of various habits of the Ailuropoda melanoleuca, as well as offering valuable information in the establishment of the animal's natural reserve system.

Behavior

Communication

The giant panda is a lonely animal. One of their ways of communicating is through chemical signals. These animals have a highly developed sense of smell.

In their habitat, these animals usually limit most of their activities to a range between 4 and 6 kilometers. Considering this behavior, the smell works to establish contact and share information between the animals that live in the same space.

This species has a large scent gland, located under its tail, surrounding the anus. When the panda wants to leave an olfactory message, it rubs its anus against trees, grass or rocks.

The chemical can transmit information related to sex, whether you are young or adult, and even your social status to other members of your species.

This chemical marking fulfills a different function than if it was done by a male or a female. Males apparently use scent to mark the territory they inhabit, while females use it to signal that it is in its estrus period.

Social

Giant pandas are solitary, although they may occasionally join each other outside of the breeding season. They are most active during sunset and sunrise. The remaining time they are generally at rest, resting in the bamboo forests.

They mark their territory with their claws, urine and the substance they secrete from their anal gland. They do not tolerate invasions of their space by other members of the group, with the exception of puppies. Therefore, by delimiting the area they try to avoid any conflict with another panda, with whom they share the territory.

Almost exclusively, social activity is restricted during female estrus and consequently during the mating period. In this reproductive stage, the male locates the females by their smell and by vocalizations.

Despite being calm and peaceful animals, during mating the male can become aggressive, if he needs to compete with another male in order to copulate with a female.

Feeding

Pandas belong to the carnivore family and almost all of their organs correspond to the digestive system of a carnivorous mammal. Although possibly some of its ancestors were carnivores, the current giant panda has a highly vegetarian diet.

Although the diet of this animal is based on a variety of around 30 different species of bamboo, they also tend to eat mushrooms, flowers, vines and grasses. It may sporadically eat some insects or fish, thus trying to complete its protein requirements.

Your digestive system is partially adapted for processing bamboo. The throat is hard and the esophagus is covered to protect it from possible injuries caused by bamboo splinters when passing through that organ.

The stomach also has a muscular lining that prevents any damage during the digestive process. Although your colon is enlarged, your intestine is short. This hinders the cellulose metabolization process, therefore the panda's body cannot efficiently absorb the nutrients from the bamboo.

Because of this, Ailuropoda melanoleuca must ingest large amounts of food to obtain the nutritional levels they need. They consume between 15 and 30 kilograms of bamboo stems or leaves daily.

Reproduction

In giant pandas, once the egg has been fertilized, its implantation in the uterus is delayed. This delay could be related to the seasonal nature of reproduction, since this way the young will be born at the best climatic moment.

When the female starts oestrus they are not very active. However, they later become restless, their vulva swell, and they lose their appetite. Embryonic development lasts about two months. In total, the gestation period has an average duration between 90 and 184 days.

Reproduction is seasonal, generally occurring between the months of March to May. Pandas are solitary animals, coming together almost exclusively to reproduce. Males cluster around females in heat, aggressively competing with another male for the opportunity to mate.

Initially, these encounters between males are characterized by escalating aggression. Once one of the specimens dominates, the levels of aggression decrease markedly, changing to an aggression of the vocal or chemical type, without physical contact.

Breeding

At birth, the young weigh between 85 and 140 grams and their bodies are covered in fine fur. They are blind, which makes them defenseless against any action by a predator. They can open their eyes at three weeks and move on their own at 3-4 months.

After birth, the female places her young in a suckling position. The young drink breast milk about 14 times a day, and are weaned at approximately 46 weeks. During the first weeks of life, the mother uses her front legs and wrists as a “cradle” to snuggle the baby against her body.

Giant pandas, unlike bears, do not hibernate. However, females use tree cavities or rock caves to raise their cubs. The close relationship between the mother and her calf can last about 18 months.

References

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