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Komodo Dragon (Varanus komodoensis) Fact Sheet: Reproduction & Development

Komodo Dragon (Varanus komodoensis)

Courtship

  • Sexual maturity for both males and females occurs between 5 and 7 years (Data from managed population indicates first reproduction for females occurs 7-10 years)
  • Sex ratios (Tim Jessop, personal communication, 2017, unreferenced)
    • Genetic testing used to diagnose sex
      • Morphological approaches (e.g., Auffenburg 1981) are less accurate
        • See Halverson and Spelman (2002)
    • Sex ratios among age stages not well known for wild populations
    • From hatching until maturity, sex ratios appear to be approximately 1:1
    • In breeding individuals, females experience reproductive costs
      • May decrease life expectancy, leading to a male-biased sex ratio among adult Komodo dragons
    • Also see Laver et al. (2012)
  • Courtship and mating in Zoos and the field have been observed from Jan 19-October 1. Successful coition from June 28 to October.
  • Territories are not established. Courtship and mating takes place in small aggregations of Komodos near carrion (other lizards usually mate alone).
  • Monitors (like fishes and some birds) have a very brief courtship. Mating occurs quickly. Attacks of males upon females are common at the time of, and immediately after, copulation. Most female acts are agonistic (use teeth and tails) during early phases of courtship. Males must be able to completely restrain females in order to remain uninjured.
  • Visual display is not significant. Other cues: rubbing chin on top of body and neck of female. Hard scratches to back. Tongue-licks to area around hind legs, shoulders, neck and head
  • Mounting occurs several times in each courtship sequence

Nesting

  • Nest is an excavation in soil or in nests of megapods (mound-builder birds)
  • 1-30 eggs laid in a clutch (average is 18)
  • Females may lay one or more eggs several times during several, successive days. Most females lay only one clutch per year. (July to early September)
  • Eggs of all varanids have a soft, leathery shell.
  • Incubation: 2.5 - 8 months (probably dependent on temperature and soil moisture)
    • 220 days when in managed care
  • Young appear in April or May and may remain together in small groups for several months. Hatchlings weigh about 80 g (2.8 oz) and average length 49 cm

Gestation and Birth

  • Young are arboreal during their first year
  • Adults largely terrestrial and rarely climb. May construct burrows along vertical banks of stream beds or under boulders and fallen trees. May also spend the night sleeping in high grass or dense brush.
  • Female breeding ability thought to decline around age of 20 and cease around 30 yrs

Longevity

  • About 30 years; more study is needed

Finding Safety

a young komodo dragon in a tree

Young komodo dragons live in trees their first year to avoid predators.

Image credit: © San Diego Zoo Global. All rights reserved.

Page Citations

Auffenberg (1981)
IUCN/SSC CBSG (1994)
Judd & Bacon (1977)

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