Komodo Dragon (Varanus komodoensis) Fact Sheet: Diet & Feeding

Opportunistic carnivores

(Harlow et al. 2010; Purwandana et al. 2016)

• Feed on a wide variety of prey
• Actively hunt; also feed on carrion

Diet items

• Adults
  • Wild boar
  • Sunda deer
  • Water buffalo
  • Large snakes
  • Occasionally, smaller Komodos
  • Less commonly, goats
    • Only occurs near human habitation
• Hatchlings feed exclusively on insects
  • Beetles and grasshoppers
• Small-size Komodo dragons
  • Smaller lizards
  • Insects
  • Birds and their eggs
• Medium-size Komodo dragons
  • Rodents: rats, shrews
  • Birds: megapodes and various small species
  • Reptiles: geckos, skinks, and small snakes

Prey detection

• Varanids have snake-like tongues (unlike most lizards, which have broad, flat tongues for food handling)
  • Tongue extended and moved up and down, sampling the air in front of mouth
  • When retracted, carries odor molecules into mouth to the vomeronasal organs
    • See Olfaction
  • Lack tastebuds

Prey capture

• Jaws close rapidly, enabling capture of fast-moving prey
• Prey is held, or sometimes thrashed, until movement ceases
  • Small prey is swallowed whole, usually head first
  • Large prey is sliced in pieces and devoured
• Venom-producing glands produce venom in Komodo dragon's saliva (Auffenberg 1981; Fry et al. 2006; Fry et al. 2009)
  • Allow Komodo dragons to kill large or fast prey

Ingestion

• Large prey torn apart
• Swallow by pushing prey down throat while flexible jaws move forward to engulf flesh
  • Hyoid apparatus (skeletal structure the tongue attaches to) moves food back to esophagus
  • Neck muscles bend from side to side to move food through the esophagus
• Ingestion rate
  • May be as much as 2.5 kg/min — higher than any other predator, except large snakes
  • A 50-kg female was observed to swallow a 31-kg boar in 17 minutes
• Large Komodos kill about 1 large prey ungulate (deer or boar) per month
  • Supplemented with small prey, such as birds and rats

Digestion

• Komodos drink from water holes after a heavy feeding
• High digestive efficiency (70–90%)
  • Time is dependent upon ambient temperature
    • Normal body temperature: about 26 hours
    • Cool nights can delay complete digestion by up to 5 days
    • Stress can slow or even stop digestion
      • Defecation of partially digested prey may occur

Excretion

• Varanids regurgitate gastric pellets of undigestible materials
  • Pellet contents: hair, feathers, partially digested bones, hooves, teeth, and claws
  • Excretions covered with a semisolid, white uric acid paste

Komodo dragons possess resistance to the harmful bacteria found in the carrion they consume. Their serum has been found to contain innate immunity to many types of bacteria (Merchant et al. 2013). Gene clusters encoding antimicrobial peptide genes have been identified (van Hoek et al. 2019).

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

Auffenberg (1980, 1981)
Burden (1927)
Fry et al. (2006)