Notable features of the skeleton include:

• postscapular fossa on caudal border of scapula (1) (Fisher, 2011)

  • The scapula is the shoulder bone (Fisher, 2011).

  • A fossa is a depression in the bone (Fossa, n.d.).

  • well-developed in ursids but not as much in procyonids (Fisher, 2011)

  • Function:

    • It connects to the subscapularis muscle to fix glenohumeral joint, which aids in climbing (Fisher, 2011).

• sharp, semi-retractable claws (2) (Fisher, 2011)

  • Functions:

    • These are used for climbing (Fisher, 2011).

• small head (3) (Fisher, 2011)

• no pronounced rostrum (4) (Fisher, 2011)

• 7 cervical vertebrae (5) (Fisher, 2011)

  • These are the neck bones on the spine as shown (Fisher, 2011).

• 14 thoracic vertebrae (6) (Fisher, 2011)

  • These are the upper back bones on the spine as shown (Fisher, 2011).

• 6 lumbar vertebrae (7) (Fisher, 2011)

  • These are the lower back bones on the spine as shown (Fisher, 2011).

• 3 sacral vertebrae (8) (Fisher, 2011)

  • These are part of the pelvic bones of the spine as shown (Fisher, 2011).

• ≤ 19 coccygeal vertebrae (9)

  • These are part of the tail bones of the spine as shown (Fisher, 2011).

• prominent humeral entepicondylar foramen (10) (Fisher, 2011)

  • absent in ursids and canids (Fisher, 2011)

  • Functions:

    • This hole in the end of the bone that connects the shoulder and the elbow transmits the medial nerve but not the brachial artery (Fisher, 2011).

      • similar to procyonids (Fisher, 2011)

      • In mustelids and feliforms, both pass through the supracondylar foramen (a similar hole in the humerus) (Fisher, 2011).

• Straight shaft of femur bone (11) (Fisher, 2011)

  • similar to ursids and procyonids (Fisher, 2011)

• moderately developed greater trochanter of femur bone (12) (Fisher, 2011)

  • The greater trochanter of the femur bone can be seen towards the outside part of the hip in the image (Fisher, 2011).

• tibia and fibula joined by synovial joints both proximally and distally (13) (Fisher, 2011)

  • This is a primitive feature that allows adjustment to uneven surfaces by cushioning the connection between the tibia and fibula bones (Fisher, 2011).

The digestive tract of the Red Panda is similar to other mammals classified as carnivores although the Red Panda has a predominantly herbivorous diet (San Diego Zoo Wildlife Alliance Library, 2021). They have a simple stomach and short gastrointestinal tract (San Diego Zoo Wildlife Alliance Library, 2021). This short gastrointestinal tract is designed to only digest easily broken-down foods (San Diego Zoo Wildlife Alliance Library, 2021). During digestion, the food is mechanically broken down in the mouth then sent via peristalsis in the esophagus into the stomach to undergo further chemical breakdown (Fowler et al., 2013). After leaving the stomach, it enters the duodenum of the small intestines then passes to the jejunum, and finally the ileum before entering the colon also known as the large intestines (Fowler et al., 2013). In the colon, the digested material passes from the ascending colon to the transverse colon to the descending colon before entering the rectum and leaving through the anus (Fowler et al., 2013). The small intestines, which includes the duodenum, jejunum, and ileum is used mainly for nutrient and water absorption of digested food (Fowler et al., 2013). If the small intestines is not very long, the digested material does not spend much time breaking down via the small intestinal secretions and providing nutrients for the small intestines to absorb (Fowler et al., 2013). The large intestines main role is to absorb any remaining nutrients and water then eliminate the waste (Fowler et al., 2013). Again, in a short digestive tract, there is not much time for absorption, so the colon is predominantly expelling waste (Fowler et al., 2013).

The circulatory system of the red panda is a closed circulatory system like other mammals including the heart, blood vessels, and blood that travels in a unidirectional cycle within the blood vessels and heart (Fowler et al., 2013; Georgia Tech Biological Sciences, n.d.). It functions to provide the organs and tissues with the nutrients needed for metabolism (Fowler et al., 2013). The heart has four chambers that blood moves through (Fowler et al., 2013). The right atrium receives deoxygenated blood from the cranial (superior in humans) vena cava, caudal (inferior in humans) vena cava, and coronary sinus and moves it to the right ventricle through the right atrioventricular orifice of the right atrioventricular valve (tricuspid valve in humans) after an action potential by the cardiomyocytes of the walls of the heart (Fowler et al., 2013). Once the right ventricle is filled, another action potential send the deoxygenated blood through the pulmonic orifice of the pulmonic valve to the pulmonary artery into the lungs to become oxygenated (Fowler et al., 2013). The oxygenated blood travels through the pulmonary vein to the left atrium (Fowler et al., 2013). Once the left atrium is filled, an action potential causes the heart to contract again to push the blood through the left atrioventricular orifice of the left atrioventricular valve (bicuspid valve in humans) to the left ventricle (Fowler et al., 2013). The left ventricle fills with blood before undergoing another action potential to push the oxygenated blood through the aortic orifice of the aortic valve to the ascending aorta (Fowler et al., 2013). The blood travels through the aortic arch and descending aorta to supply the rest of the body with oxygenated blood via diffusion in the capillaries (Fowler et al., 2013). The deoxygenated blood from tissues enters the veins and travels back to the heart (Fowler et al., 2013). The arteries mainly consist of oxygenated systemic blood and the veins mainly consist of deoxygenated systemic blood (Fowler et al., 2013).

The respiratory system consists of all the structures needed to conduct gas exchange, which includes the lungs, chest cavity, muscles, heart, blood, blood vessels, and brain (Fowler et al., 2013). Atmospheric air is breathed in through the nasal cavity after the diaphragm creates the negative pressure to began inhalation (Fowler et al., 2013). Then it passes through the larynx and pharynx to the trachea and then lungs where it travels through the primary bronchi to the smaller bronchi to the bronchioles then the respiratory bronchioles and finally to the alveolar ducts that lead to the alveoli (Fowler et al., 2013). From the alveoli, oxygen is transferred to the blood through capillaries and travels to the heart, where it signals the brain to either slow down or speed up breathing based off of how much oxygen is there (Fowler et al., 2013). Then from the heart, the oxygenated blood is pumped to the muscles, where it oxygenates the tissues through the capillaries (Fowler et al., 2013). Then carbon dioxide waste from the tissues enters the capillaries into the blood to travel back to the heart, which signals the brain to slow or quicken breathing again (Fowler et al., 2013). Then from the heart, the blood moves back to the lungs, where the carbon dioxide is exchanged for oxygen and expelled through the nostrils (Fowler et al., 2013).

• Red pandas only interact during mating season in which they participate sexual reproduction (Swyers, 2017).

• Mate between January and March with more than one partner (Swyers, 2017).

• 112 to 158 day gestation period (Glatston et al., 2015; Swyers, 2017)

• Can give birth to 1 to 4 cubs (Glatston et al., 2015; Swyers, 2017)

• Each cub can weigh 3.9 to 4.6 oz (Swyers, 2017).

• The mother spends 60 to 90 percent of her time caring for young (Swyers, 2017).

• After 18 days the cubs can open their eyes (Swyers, 2017).

• After 90 days of age the cubs achieve adult coloring and eat solid food (Swyers, 2017).

• They are fully weaned at 6 to 8 months old (Swyers, 2017).

• Reproduce starting at 18 months (Swyers, 2017)

• Fully mature at 2-3 years old (Swyers, 2017)

• Average lifespan is 10 to 15 years (Swyers, 2017)

• Typically live alone and are territorial (Swyers, 2017)

• They are nocturnal omnivores that eat mostly bamboo and other plants, also insects birds and fish (Swyers, 2017). They do most of their hunting at night (Swyers, 2017).