When an animal exclusively reproduces this way, the process is called obligate parthenogenesis. For animals that usually reproduce sexually this process is called facultative parthenogenesis and it is very rare.
Komodo dragon
Scientists first discovered that the Komodo dragon (Varanus komodoensis) could have virgin births in 2006. At the time, . One of these dragons, a female at the Chester Zoo in the U.K. gave birth to a clutch of 25 eggs, despite never being in any contact with males.
Sharks
One ordinary morning at Omaha’s Henry Doorly Zoo and Aquarium, zookeepers were stunned to find a 6.5 inch (16.5 centimeters) juvenile shark in a tank containing three female bonnethead sharks (Sphyrna tiburo). None of the female bonnetheads had ever been exposed to males of the species within captivity, and they bore no mating scars from different species within the tank.
California condor
In hopes of helping the population rebound, researchers at San Diego Zoo housed female condors with a fertile male. But apparently the male wasn’t necessary: Geneticists testing DNA samples within the lab discovered two male chicks that carried two identical copies of their mother’s DNA.
Stick insects
Unlike other animals, parthenogenesis in stick insects is not rare. In fact, creatures within the genus Timema reproduce exclusively in this way — and have done so for a million years.
Blind snake
The brahminy blind snake (Ramphotyphlops braminus) is another species thought to only reproduce asexually. Only female individuals of this species have ever been found.
Tardigrades
Tardigrades are aquatic, microscopic creatures known for their ability to withstand extreme conditions. These chubby water bears can go both ways, reproducing both sexually and asexually. However, parthenogenesis is only common in lake and terrestrial habitats.
Crocodiles
This year scientists described the first known case of a virgin crocodile birth. After spending 16 years away from other males, a female American crocodile (Crocodylus acutus) produced a clutch of 14 eggs.
The female crocodile arrived at the Costa Rican zoo, Parque Reptilandia, in 2002. She spent all her time after that alone in her enclosure.
