Male Komodo dragons compete for the chance to mate with females. They wrestle while standing on their tails for support, using their forelegs to grab each other and try to throw their opponent to the ground. Sometimes, they get injured, and the loser either runs away or lies still.
Female Komodo dragons lay about 25 eggs, roughly the size of grapefruits. They dig nests in the ground to incubate their eggs, but they only produce one clutch each year and may not breed every year. Females either make their own or use nests built by mound-nesting birds to protect their nests. They often dig fake nests to confuse predators, including male dragons and other females.
The eggs take up to nine months to hatch. Young Komodo dragons live in trees to stay safe from predators and eat small animals. They will eat anything that fits in their mouths, including eggs, grasshoppers, beetles, and geckos. They are large enough to live on the ground when they reach about four years old and grow to around four feet long. Females usually become sexually mature at nine years old, while males do so at ten years old.
Komodo dragons have a unique way of reproducing: they can do it both sexually and asexually through a process called parthenogenesis. In both male and female dragons, meiosis occurs, which is how cells divide to form sex cells—sperm in males and eggs in females. In females, meiosis creates four cells that can become eggs, but usually, only one of these cells develops into a viable egg, while the other three are absorbed by the mother's body. This means that the offspring produced by this method share genetic material with their mother.
However, these hatchlings are not exact copies of their mother because genetic mixing happens during egg production. This ability allows female Komodo dragons to start new colonies on their own. For example, a female could swim to a new island and lay a clutch of eggs without needing a male.
The drawback of parthenogenesis is that all the resulting hatchlings are male. These males could grow up and mate with their mothers, so within one generation, the population could continue reproducing on the new island. Over time, this practice, similar to the Oedipus myth, could lead to health problems because of inbreeding, resulting in low genetic diversity within the population.