Developmental plasticity in an unusual animal: The effects of incubation temperature on behavior in chameleons…

[kinyonga]

“Cold-incubated animals were more sedentary, caught prey faster, and extended their tongues farther to reach prey than did their warm-incubated counterparts. Thus, the fitness costs of low temperatures in the nest (slow development, and thus late hatching) may be offset by incubation-derived enhancements in hatchling growth rates and foraging abilities.”…
https://ro.uow.edu.au/cgi/viewcontent.cgi?article=2006&context=smhpapers1

 

[kinyonga]

More on incubation methods effects on hatchlings…
“The highest incubation temperatures were disruptive to development; eggs had high mortality, developmental rate was low, and hatchlings grew slowly. Changes in temperature during incubation increased the among-clutch variance in incubation length relative to that of constant temperature treatments.”…
https://pubmed.ncbi.nlm.nih.gov/18512704/

“I conclude that the veiled chameleon has genetic sex determination (GSD) and that anecdotal accounts of temperature- dependent sex determination (TSD) for this species, and other chameleons are likely to reflect reporting or statistical bias.”…
https://www.faculty.biol.vt.edu/andrews/WebPage/WebPage/pdfs/And_TSD.pdf

“Our results suggest that neither water availability nor water uptake by eggs affect the length of diapause but that an increase in ambient temperature initiates development of diapausing embryos of C. calyptratus.”…
https://pubmed.ncbi.nlm.nih.gov/15286942/

“Because most of the viable range of incubation temperatures for the veiled chameleon was included in the experiment, if TSD occurred in this species, it ought to have been exhibited in the sex-ratio of the hatchlings. However, after comparing sex ratios at all temperatures, no significant differences existed.….
“It was noted that the chameleons that hatched in from eggs in the 29°C incubation were much more active, immediately post hatching, than hatchlings from either the 26.5°C or 24.5°C temperatures. In addition, the individuals from the higher temperature had a greater appetite immediately after hatching than those of the other two groups. Hatchlings from the warmest temperature began consuming crickets within hours of hatching, whereas the others started to eat after 12-24 hours. This may indicate that higher incubation temperature results increased metabolism at the time of hatching. However, this was not tested by any objective means.

After hatching, all chameleons were reared in similar habitats under nearly identical conditions. The chameleons were observed in a general way for about five weeks post hatching. During that time, growth rates, food consumption, and activity level were similar between all groups, and no hatchling mortality was observed. There did not appear to be any persistent developmental influence of their incubation temperature.”…
http://www.chameleonnews.com/08FebLong.html