Snakes and Lizards
Location: Main Court, Lizards, Snakes, and the Tuatara Case
There are many organisms capable of reproducing without fertilisation of egg cells by sperm. This process, known as parthenogenesis, is rare in vertebrate animals, but it is found in some species of reptiles. In particular, some species of Whiptail Lizards (Aspidoscelis uniparens, not displayed here) are entirely female – there are no males. This is thought to be due to hybridisation between different species of Whiptail Lizards.
As there are no males, there is no exchange of gametes or male-female sexual behaviour. Nonetheless, sexual behaviour is observed in these lizards, even though it does not contribute to sexual reproduction. This makes the Whiptail Lizard one of the few animals with well documented same-sex sexual behaviour. This behaviour goes beyond displays or occasional occurrences – ‘mating’ between females is regularly observed. Whiptail Lizards are therefore an important part of the study of same-sex behaviours in the natural world.