Captive Breeding Programmes – Dragons

Reaching lengths of up to 10 feet (3m) Komodo Dragons are the world's largest living lizards and they can weigh up to 10 stone or more. Native to the island of Komodo and also the Indonesian islands of Flores, Gili Dasami, Gili Motang and Rinca, these giant monitor lizards only became known to western science in 1910. Since their discovery, habitat loss and the poaching of their natural prey has led to reduced numbers, leaving them as an endangered “Red List” species and today fewer than 5,000 are estimated to be left in the wild. (more scarily is that the American museum of natural history suggests there could be as few as 350 breeding females left in the wild today)

Captive breeding programmes have been successful for most endangered species, but when it comes to breeding dragons in captivity, problems have emerged. One of the biggest is the difficulty in sexing these giant monitors as it’s virtually impossible to tell male from female.
As if that wasn’t enough of a setback, Komodo Dragons tend to be rather picky when it comes to choosing a mate – This means that if a zoo were to find a 'True pair' they are not guaranteed to get on or mate anyway
Despite this, there have been some notable successes. In 1992, America’s National Zoo in Washington managed to hatch 13 out of 26 eggs, followed a year later by two successfully hatched clutches at the Cincinnati Zoo. All in all, of some 300 specimens of dragons living in captivity around the world, nearly two-thirds are captive-bred juveniles.
However the strangest examples of captive breeding was in the UK in 2006 and 2007, when female dragons at London and Chester Zoos, produced youngsters by virgin birth!
Many animals have the ability to reproduce asexually, something which is known to biologists as parthenogenesis, and a number of reptile species adopt this approach. However, no one had seen parthenogenesis in Komodo Dragons before which opens up some interesting possibilities for these vulnerable animals.
If the virgin birth route proves to be something which all dragons can do, rather than a uniquely British accidental anomaly of some kind, then the low estimated numbers of wild-living, breeding females might be less alarming than it first appears. In addition, it could potentially offer a way round the incompatibility issue that seems to cause so many problems for the more traditional approach to sexual reproduction.
It remains to be seen if the potential of parthenogenesis is really likely to offer anything useful in terms of saving the species – but for the moment at least, it certainly would appear to offer a glimmer of hope.
The Komodo Dragon may not be the beast of our myths and legends, but it does have a good 4 million years of history behind it and is the largest lizard in the world, which demands a good deal of respect, however hard it is to breed in captivity.