For the most part, a panda is a medium-sized bear but can still seriously injure or even kill anyone who infuriates it. A large female can weigh …
The panda: a carnivore turned herbivore
Pandas can only consume bamboo, but they assimilate almost the same nutrients as wolves—a surprise to the biologists.
In that case, he is a known omnivore: That would make the giant panda a true omnivore! Living on bamboo all day, every day, is impossible for a carnivore. Anomalies that perplex us: what if the giant panda, widely recognized as a sign of an endangered species, were an evolutionary’s final stop?
Doubt is tolerated. Let’s focus on its digestive system, shall we? Chains of polymers such as cellulose must be broken down to remove the total amount of nutrients. Although herbivores have evolved to increase the retention time of material in their intestines, pandas have a short, straight, and simple gastrointestinal tract like a carnivore.
Why did the giant panda switch to that particular diet?
The Ailuro, the giant panda’s ancient ancestor, was found in marshes, not in trees, as modern pandas do.
Ailurarctos branch developed into Ailuropod microta, a smaller version of today’s giant panda, but slightly larger than Ailuractos, which inhabited large areas in southwest, south, central and northwestern China. This population spread about 3 million years ago, when A. microta appeared, coincided with a dietary change to bamboo.
Ailacus' fossils have shown that this species evolved in marshes with the absence of bamboo in mind. During the period of A.microtae, it was warm and humid, allowing bamboo forests to spread.
However, there is only one great panda, so it avoids competition with the other food community members by feeding on bamboo, which is available all year round, plentiful, and preferred.
These characteristics explain how this initially carnivorous diet changed over time to an increasingly advanced one based on bamboo. But what are the genes telling us?
2009, the scientists at the Chinese Academy of Sciences declared that the Giant Panda genome had been completely sequenced. Subsequently, we will do more detailed studies, in particular, to learn how the pandas' diet has evolved through genetics.
Studies show that pandas have lost their ability to taste food: “to distinguish foods, among those qualities, there are five essential tastes: sweet, sour, salty, bitter, and savory” or umami “(from a Japanese term meaning delicious). The actual flavor associated with protein-rich foods is created by interacting with the taste buds' receptors with carboxylic acid (glutamate). However, of the three acid receptor forms, only the T1R1 is functional in the giant panda because of mutations in the corresponding gene. Thus, panda bears are seen as herbivorous by many people, mainly because of genetic mutations, which at least partly conceal the true carnivorous nature. Therefore, it is said that it is herbivorous by nature.
However, this doesn’t seem very specific. The estimated age of this gene is approximately 4.2 million years. Nonetheless, the transition was slow and methodical. It lasted for at least 7 million years (as reflected by fossil teeth) (the fossils discovered at this period are very similar to those of the current giant panda, suggesting that it completed transition at this time). Diet changes could result in the pseudogenization of T1R1.
The same researchers discovered that the panda’s dopamine metabolic mechanism could be imperfect, which would affect its reward system (dopamine acts positively on the brain, notably responsible for addiction phenomena; dopamine thus plays an essential role in food behaviors). They posit that some aspects of bamboo could aid catecholamine metabolism, raising dopamine’s energy level. Therefore, the writers speculate that pandas may have switched to bamboo to compensate for this lack of dopamine. Further, analyses on the nervous system chemicals in bamboo will allow us to learn.
To date, numerous theories have been put forward as the cause of the giant panda’s dietary change, although none has been able to affirm this.
To date, pandas do not know why they started to eat bamboo.
Low diversity of digestive bacteria
They then compared their findings with those of the carnivores (lions, hyenas, tigers), herbivores (rabbits, grizzly bears), and omnivores (bears) of the polar bear. The microbiota of the panda is more bear-like and tiger-like than that of herbivores. Furthermore, the panda has reduced bacterial diversity regardless of the diet. According to the researchers, a more diverse microbiome makes for a healthier response to environmental change. Finally, the flora of the panda’s gut differs according to the seasons, becoming least diverse in the autumn. Is the only motive for the panda to consume bamboo pleasure or food? Consequently, however, but without initial discovery, several questions are still left to be addressed, including why bacteria are present to break down meat, even after such a time of nonuse.
A time-consuming activity
Bamboo moves quickly into the panda’s intestinal tract and is not well-digested by the panda. They must consume a lot of food to keep their digestive system functioning well.
Additionally, it is known that the leaves of bamboo have six times the nutritional value, if not more than the roots and the stalks.
An animal develops more efficiently in its eating habits and becomes better able to get food with age. Increased physiological functions combined with the growth of teeth and the digestive system’s development occurred during this evolution. As we age, the quality of our eating activity declines.
What do they eat other than bamboo?
A giant panda mainly feeds on bamboo and eats fruit, bird eggs, or dead animals. Pandas have been found in villages looking for food, too.
And in captivity?
Pandas get bamboo at will or nearly in captivity. To imitate what happens in the wilderness, the types and components of the provided bamboo vary by year and, at times, by individual tastes.
The species supplied are either native if approved by pandas, species, or imported species. They mostly come from around the mountains in China, though they come from horticultural bamboo groves in general outside of China.
The needs are massive, as pandas usually are twice as giant as intake. Since the bamboos are already cut, they are abandoned, and new fresh bamboos are sold, which are later dispersed or remain in an area too long. Consequently, bamboo management is usually a zoo challenge.
However, the nutritional deficiency needs to be compensated by a supplementary diet of captive pandas because of the small number of bamboo species. Concentrated grain-based foods delivered in captivity for bamboo supplement do not exceed 10%, preferably 5% of the diet.