temperature-dependent sex determination

reproduction

Also known as: TSD

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Last updated

July 19, 2026

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Temperature-dependent sex determination (TSD) is a reproductive strategy where the temperature of the nest during embryonic development controls the sex of the hatchlings, rather than genetic factors like sex chromosomes. This phenomenon is observed in some lizard species, such as certain iguanids, geckos, and wall lizards. In most turtles, higher temperatures produce females, while lower temperatures produce males. Conversely, many crocodiles produce females at cooler temperatures. This contrasts with the genetic sex determination common in most mammals and many reptile species.12

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reptile
Embryonic development and parental care
Temperature-dependent sex determination (TSD), discovered in the early 1970s, is the most researched of these factors. The sex of the offspring in species with TSD is influenced by the temperature during one critical period of incubation, instead of by hereditary factors. In most turtles females…
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Temperature-dependent sex determination (TSD), discovered in the early 1970s, is the most researched of these factors. The sex of the offspring in species with TSD is influenced by the temperature during one critical period of incubation, instead of by hereditary factors. In most turtles females…
Read More