Which reptile species consists entirely of females in the wild?

The New Mexico whiptail lizard is the reptile species that consists entirely of females in the wild. Its scientific name is Aspidoscelis neomexicanus, and it lives in parts of New Mexico, Arizona, and northern Mexico.

Because there are no males, the species reproduces by parthenogenesis: females lay eggs that develop without fertilisation. The New Mexico whiptail arose through hybridisation between the little striped whiptail and the western whiptail. That hybrid origin disrupts normal sexual reproduction and prevents healthy males from forming, while preserving the ability to produce female offspring.

A common misconception is that these lizards reproduce without any courtship-like behaviour. Females may mount or court one another, a behaviour thought to stimulate ovulation. Each female can lay several unfertilised eggs, allowing a population to persist despite having only one sex. The species is also New Mexico’s official state reptile. Its all-female biology is unusual, but it is part of a broader pattern of parthenogenesis found in several whiptail lizards.