Bearded dragon: what a landmark study changes about how reliable sexing really is
Published by Planète Pets · managing editor: Clément Lacaille · how our guides are written
Like many Australian lizards, the bearded dragon (Pogona vitticeps) has ZW sex chromosomes that genetically determine its sex. A study by Quinn, Georges, Sarre, Guarino, Ezaz and Graves, published in 2007 in the journal Science, showed that incubation at high temperature can hatch genetically male (ZZ) individuals that nonetheless develop into functional females. Find all our precision gear in the accessories section.
Contents · 5 sections
Two sex-determination systems that coexist
Between roughly 20 and 32 °C, the classic chromosomal system dominates: genetic sex matches observed sex. Above roughly 34 °C of incubation, a growing proportion of genetically male individuals develop into anatomically and reproductively functional females, up to nearly all females at very warm incubation regardless of the starting chromosomal sex.
Why this discovery stood out in research
The bearded dragon was one of the first vertebrate species shown to have a genetically determined sex that temperature alone can override, a dual sex-determination system that has since fed into research on the evolution of chromosomal systems and on how sensitive some species might be to climate warming in the wild.
What this means for sexing a juvenile
For an owner, this discovery puts into perspective how reliable an early sexing call on a juvenile bearded dragon really is, particularly if it came from a high-temperature incubation: a female anatomical appearance does not necessarily rule out underlying male chromosomes. Examining the femoral pores and the base of the tail, done at an older age, remains the most reliable way to confirm functional sex.
What this does not change about bearded dragon care
This mechanism only concerns the egg incubation stage and does not change the needs of an adult bearded dragon, male or female: diet, UVB and basking spot follow the same standard guidelines for the species regardless of the original chromosomal profile.
- Main finding: incubation above roughly 34 °C produces functional females even from genetically male (ZZ) individuals.
- Scientific significance: first demonstration in a vertebrate of a complete genetic sex reversal driven by temperature.
- Practical implication: early sexing of a juvenile from a warm incubation is worth confirming later by physical examination.
- What it does not change: standard adult care needs, independent of this incubation mechanism.
This topic connects with our guide to basking lamp orientation for bearded dragons, and complements our guide to choosing a terrarium thermostat, essential for any properly controlled incubation.
FAQ
Are all bearded dragon females from warm incubation genetically male?
No, only part of the genetically male individuals are affected at these temperatures; the phenomenon affects a growing proportion but not systematically every individual.
Can these sex-reversed females reproduce?
Research shows they remain reproductively functional, with studied implications for passing this trait on to the next generation.
Should this be a concern for an adult bearded dragon adopted later in life?
No, this mechanism only concerns egg incubation; an already-developed adult follows the species' standard needs regardless of this phenomenon.
In our shop, for this use: Stick-on digital thermometer for aquarium and terrarium glass (€18.90) · the whole shop
This guide is part of Planète Pets’s Reptiles universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.
