Virgin births at ZSL London Zoo
Thursday 21 December 2006
Four Komodo dragons hatched at ZSL London Zoo earlier this year were the result of parthenogenesis - the development of an egg without fertilization by a sperm.
A clutch of dragon eggs laid by adult female Komodo dragon Sungaï in August 2005 immediately fascinated reptile keepers at ZSL London Zoo. Sungaï arrived at London on loan from Thoiry Zoo in France in early 2005 and the clutch of eggs was laid more than two years since she had last lived with Thoiry's male, Kimaan. Since Sungaï hadn't yet met ZSL London Zoo's male Raja it was first thought she may have stored Kimaan's sperm for more than two years. However, the Zoological Society of London's (ZSL) Curator of Herpetology, Richard Gibson, wasn't entirely convinced and resolved to investigate further.
Genetic fingerprinting techniques at Liverpool University have confirmed that the four dragons were actually the result of parthenogenesis. Sungaï later mated with Raja and subsequently laid a second small clutch of eggs from which a single, 'normal', dragon hatched, demonstrating that Komodo dragons can switch between asexual and sexual reproduction depending on the availability of a mate. The fact that Komodo dragons can reproduce asexually, and switch 'at will' back to normal sexual reproduction was completely unknown.
ZSL’s Curator of Herpetology Richard Gibson said: "I am delighted that the mysterious parentage of our Komodo dragon babies has been solved and that we have discovered something new to science at the same time. Knowing that the world's largest lizard can reproduce like this suggests that many other reptiles may also do this more often than we thought and may lead to changes in the way we manage this and other species in breeding programmes. This discovery also raises important questions about the natural history of dragons in the wild and will therefore help to safeguard the future of the species."
A full report into the findings, written in collaboration with the University of Liverpool and Chester Zoo will appear in Nature on Thursday December 21st 2006.
Liverpool University carried out the genetic fingerprinting research. Chester Zoo provided further DNA material from incubating eggs which have also proved to be produced by parthenogenesis.