Green anoles: what an incubation temperature study changes about raising juveniles
Published by Planète Pets · managing editor: Clément Lacaille · how our guides are written
Getting a pair of green anoles to lay is one thing; ending up with juveniles that grow well is another, and incubation temperature plays a bigger part than most keepers assume. A study by Rachel M. Goodman, published in 2008 in the Journal of Experimental Zoology Part A, incubated Anolis carolinensis eggs from several populations at 23.5°C, 27°C and 30°C, then measured the young weekly for eight weeks (see the study). Our setup guides are gathered in the reptile bedding and habitat section.
Contents · 4 sections
An effect that is completely invisible at hatching
Eggs incubated cooler took longer to hatch, without changing how efficiently egg mass was converted into hatchling mass. More importantly, incubation temperature altered neither the mass nor the snout-vent length of the juveniles at hatching: coming out of the egg, nothing distinguished an anole incubated at 23.5°C from one incubated at 30°C. That is exactly what makes this effect impossible to spot for a keeper who only measures on hatch day.
The gap widens over the following weeks
The difference appeared across the eight weeks of follow-up: incubation temperature significantly influenced subsequent growth, in both mass and length, with cooler incubation broadly associated with stronger growth. How large the effect was varied with the population the eggs came from, a sign that the parents' local context shapes the response. These so-called latent effects therefore cannot be read in the incubation box, but in the rearing tubs a month or two later — a good reason to keep a growth log alongside the protocol described in our guide to breeding green anoles in a terrarium.
A juvenile does not pick the same temperature as an adult
An earlier study by Goodman and Walguarnery, published in 2007 in the same journal, had already shown that incubation shapes the thermal behaviour of hatchlings (see the study). Placed on a thermal gradient within 48 hours of hatching, young from different treatments did not select the same upper limit of their temperature range. After 22 to 27 days under common conditions, those preferences converged, with the lower and median temperatures rising while the upper limit came down. This plasticity appears specific to the neonatal period and absent in adults: a wide thermal gradient therefore matters most in the first few weeks, as explained in our guide to green anole terrarium size and setup.
- 23.5 / 27 / 30°C: the three incubation temperatures compared on eggs from several populations.
- No gap at hatching: neither mass nor snout-vent length differed between treatments.
- 8 weeks of follow-up: this is where growth diverges, stronger after cooler incubation.
- 22 to 27 days: how long it takes for juvenile thermal preferences to converge again.
For anyone breeding green anoles, the practical lesson is clear: judging an incubation by the look of the hatchlings alone is misleading. It is the growth curve over the following weeks that reveals what the incubation box actually produced, and it deserves logging just as much as incubation duration does.
Frequently asked questions
Should eggs always be incubated on the cool side?
The study observes broadly stronger growth after cooler incubation, but the effect varied by population and incubation then takes longer: it does not set a universal optimal temperature.
Why is nothing visible at hatching?
Because incubation temperature changed neither the mass nor the length of hatchlings in this study: the effect is latent and only shows up in later growth.
Does a juvenile need a different gradient from an adult?
Its thermal preferences depend on its incubation during the first weeks before converging; a wide gradient leaves it the choice during that phase, which is no longer the case afterwards.
See it in the Planète Pets shop: 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.
