Giant Panda (Ailuropoda melanoleuca) Fact Sheet: Physical Characteristics

Data from (Reid & Gong 1999)

Body shape

• Stocky, barrel-shaped body (Reid & Gong 1999)
• Head (from Chorn & Hoffmann 1978; Edwards et al. 2006 unless otherwise noted)
  • Large (Reid & Gong 1999)
  • Wide, flaring cheek bones (zygomatic arches)
  • Robust chewing muscles
  • Pronounced sagittal crest down the midline of the skull
• Legs
  • Shorter than that of most bears (Reid & Gong 1999)
  • Forequarters more massive than hindquarters (Reid and Gong 1999)
    • Structure enables the animal to lift its heavy body into trees
• Feet
  • Hind-feet not completely "flat-footed" (plantigrade); lack heel pad
  • Unique front-feet have five digits plus an opposable "thumb"
    • "Thumb" is an enlarged wrist bone with attached muscles for grasping and orienting bamboo stems
• Tail
  • Short
  • Scent glands located on underside
• Paws
  • "Pseudo-thumb" for processing bamboo (Swaisgood et al. 2016)

Pelage

• Coloration striking for a mammal
  • Pattern blends well in a snowy landscape and in the forest
  • May also serve as a warning signal to other pandas (Schaller 1994)
• Overall white and black
  • Brown and white coloration has been rarely observed
  • Body white
  • Black patchces souround the eyes
  • Ears and legs black
    • Color of legs extends, in a band, across shoulders and sometimes tip of tail
• Hair
  • Short, thick wooly coat
    • Provides excellent insulation; animals can comfortably sleep on snow
    • Slightly oily fur prevents water penetration in a damp habitat
  • 5-8 cm (2-3 in) long on the shoulders
    • Shorter on the back, c.2.5-5 cm (1-2 in) in length
  • Hair on head or neck can not be raised (to intimidate potential aggressors)

Males larger than females (from Schaller et al. 1985)

• Males c. 18% heavier than females
  
• Dimorphism much less pronounced than in other bears
• In polar bears, males c. 36% heavier than females
• In grizzly bears, males up to 38% heavier than females

Male genitals

• Small and pointed to rear
• More similar to red panda than to other bears

Vision and Smell

• Poor visual acuity
  • Pupil has vertical slit like domestic cats (found in many nocturnal animals)
• Acute sense of smell

Hearing (Owen et al. 2016a)

• Functional hearing range: 0.10 kHz (lower limit) to 70.0 kHz (upper limit)
  • Good sensitivity: 10.0-16.0 kHz
  • Best sensitivity: 12.5-14.0 kHz
• Can hear into the ultrasonic range (a trait which may be an ancestral trait among mammals)
• Increases in ambient noise may mask acoustic signals, which potentially could impact reproductive success

Digestive specializations

• Unusual gut for an animal that eats only plants (Loeffler et al. 2006)
  • Length much shorter than is expected
    • Total length only 4 times the length of the body
      • Length more similar to that of meat-eating carnivores
    • Guts 10 to 22 times body length seen in other exclusive plant eaters such as deer
• Digestion considered unspecialized (Loeffler et al. 2006)
  • Stomach simple
  • No foregut fermentation
  • No caecum thus no hindgut fermentation
  • Recent genome sequencing detects no digestive enzymes specifically for plant cellulose (Li et al. 2010)
• Microbes aid bamboo digestion (e.g., Zhu et al. 2011)

Dentition

• 2nd and 3rd premolars well developed (from Chorn & Hoffmann 1978; Edwards et al. 2006)
  • Unlike the pattern seen in other bears
• Molars
  • Broad and flat with extra cusps (from Chorn & Hoffmann 1978; Edwards et al. 2006)
    • Similar to extinct plant-eating European cave bears
• Carnassial teeth (upper 4th premolar/lower 1st molar)
  • Teeth with reduced slicing capacity compared to most other carnivores (Hunt 2004)

Giant panda 'Bai Yun' at the San Diego Zoo.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Chorn & Hoffmann (1978)
Edwards et al. (2006)
Li et al. (2010)
Loeffler et al. (2006)
O'Brien (1985)
Pan & Lü (1993)
Reid & Gong (1999)
Schaller (1994)
Schaller et al. (1985)