Qinling panda

The Qinling panda (Ailuropoda melanoleuca qinlingensis), also known as the brown panda, is a subspecies of the giant panda, discovered on November 15, 1959, but not recognized as a subspecies until June 30, 2005. Besides the nominate subspecies, it is the first giant panda subspecies to be recognized.
It differs from the more familiar nominate subspecies by its smaller skull and dark brown and light brown (rather than black and white) fur, and its smaller overall size. Its eye spots are under the lower lid, instead of around the eyes. Brown pandas are exceedingly rare.
Most Qinling pandas are around the same size as giant pandas, growing to 1.2–1.8 m (3 ft 11 in – 5 ft 11 in) in length and 70–80 cm (28–31 in) at shoulder height. The males of the species are heavier than females, weighing roughly 60–190 kg (130–420 lb) whereas females are likely to weigh 75–125 kg (165–276 lb).
This subspecies is restricted to the Qinling Mountains, at elevations of 1,300–3,000 metres (4,300–9,800 ft). Its coloration is possibly a consequence of inbreeding: as the population is closed off from genetic variation and this might have led to the preservation of the mutation responsible.
There are an estimated 200–300 Qinling pandas living in the wild as of 2023, up from 100 in 2001.
On August 30, 1989, a female of this species was captured and brought to the Xi'an Qinling Wildlife Park to be mated with a regular giant panda. This panda's offspring was black-and-white, but reportedly started becoming brownish as it aged. According to other reports she gave birth to three cubs, all of whom died shortly after being born. The mother, named Dan-Dan, died in 2000.
Scientists captured a brown panda along with his mother, a black and white panda, in 2009. They called him Qizai. Research signifies that the change in color was a cause of a mutation. There was a missing sequence of DNA in a gene known as Bace2. Bace2 is a gene responsible for pigmentation in organisms. In order to verify that their findings were accurate, scientists underwent an experiment testing mice where they utilized CRISPR-Cas9, a gene-editing tool. The team was able to manipulate the sequence of the mice DNA by deleting the mutation causing segment. Researchers reported that the 78 tested mice did have genetic changes in response to the experiment. The melanosome count decreased, as well as the size of them. The coats of the genetically altered mice also had light-colored coats. Additionally, researchers were able to uncover a preserved tissue sample from Dan-Dan, where they concluded she had the same recessive trait as Qizai.
Due to the Qinling subspecies being restricted in range, it has been exposed to metal intoxicates such as copper, nickel, lead, and zinc that are now present in bamboo and soil as a result of the environmental pollution that is ongoing in China. More specifically, studies have indicated that the Qinling subspecies faces such anthropogenic threats so directly due to the fact that heavy concentrations of metals in bamboo and soil are positively correlated with high elevations, thus the Qinling Mountain range is increasingly affected.
Dental health is important for the survival of the Qinling pandas. These pandas have a survival rate of 5–20 years. The reliance on bamboo while having a carnivore digestive system results in energy and nutritional challenges and affects the oral health of these pandas. They feed on bamboo for at least 14 hours a day, which causes their teeth to wear out. The most common dental abnormalities that Qinling pandas face are dental attrition and fractures. These two abnormalities can impact the survival rate of these pandas.
In a field study, pandas in the Qinling Mountains were observed demonstrating a dietary strategy to maximize protein intake and minimize fiber consumption, further mirroring the macronutrient profiles of hypercarnivores. This approach may have facilitated the dietary transition of giant pandas by isolating the evolution of diet from more complex physiological adaptations, such as gut length and microbial composition, though it also raises questions about the evolutionary pressures that have shaped these adaptations.