Reptiles
Checkered Whiptail
Aspidoscelis tesselata · also called checkered whiptails
Across a stretch of open Texas grassland, a checkered whiptail forages briskly through the debris, a female with no male counterpart anywhere in the species, her entire lineage tracing back to a single hybrid ancestor whose unusual reproductive quirk gave rise to every individual alive today.
Overview
The checkered whiptail, Aspidoscelis tesselata, is an entirely female, parthenogenetic lizard species native to desert and grassland habitat across parts of Texas, New Mexico, and adjacent Mexico. Its unique all-clone reproductive strategy, tracing back to a single ancient hybridisation event, makes it one of the more genuinely unusual reptiles found anywhere in North America.
A species with no males at all
While most animals require two sexes to reproduce, the checkered whiptail simply does away with that requirement entirely, an all-female lineage that has persisted for generations purely through cloning descended from one single hybrid founder.
Status
Least Concern — widespread and stable across suitable desert and grassland habitat throughout its range in the southwestern United States and Mexico.
Checkered Whiptail: common questions
How does the checkered whiptail reproduce without males?
The checkered whiptail reproduces through parthenogenesis, a process in which females produce offspring without any fertilisation by a male, meaning every individual in the species is female and each generation is produced entirely without mating between two different sexes.
Why do female checkered whiptails still act like they're courting?
A checkered whiptail will sometimes perform courtship and mounting behaviour between two females despite the complete absence of males in the species, a behaviour thought to help hormonally stimulate egg production, effectively repurposing courtship behaviour that would otherwise involve a male.
Where did the checkered whiptail come from?
A checkered whiptail traces its entire lineage back to a single ancient hybridisation event between two separate sexually reproducing whiptail species, meaning every individual alive today is effectively descended from one founding hybrid female whose unusual reproductive ability allowed the new lineage to persist.
Where does the checkered whiptail live?
The checkered whiptail is native to desert and grassland habitat across parts of Texas, New Mexico, and adjacent Mexico, foraging actively across open ground in search of insects and other small invertebrates.