Effects of incubation temperature on growth and performance of the veiled chameleon (Chamaeleo calyptratus)

Abstract

I evaluated the effect of incubation temperature on phenotypes of the veiled chameleon, Chamaeleo calyptratus. I chose this species for study because its large clutch size (30-40 eggs or more) allows replication within clutches both within and among experimental treatments. The major research objectives were (1) to assess the effect of constant low, moderate, and high temperatures on embryonic development, (2) to determine whether the best incubation temperature for embryonic development also produced the "best" hatchlings, and (3) to determine how a change in incubation temperature during mid-development would affect phenotype. To meet these objectives, I established five experimental temperature regimes and determined egg survival and incubation length and measured body size and shape, selected body temperatures, and locomotory performance of lizards at regular intervals from hatching to 90 d, or just before sexual maturity. Incubation temperature affected the length of incubation, egg survival, and body mass, but did not affect sprint speed or selected body temperature although selected body temperature affected growth in mass independently of treatment and clutch. Incubation at moderate temperatures provided the best conditions for both embryonic and post-hatching development. 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.

The sooner the better: reproductive phenology drives ontogenetic trajectories in a temperate squamate (Podarcis muralis)

“…Importantly, hatching date is a complex parameter because it integers both maternal quality (laying date) and environmental conditions (incubation temperature) that exert a proximate influence on developmental rate (Andrews, 2004). In addition to phenology, thermal conditions during embryonic life have profound effects on offspring phenotype at birth, affecting a diversity of morphological, physiological, and behavioural traits (Deeming & Ferguson, 1991;Shine, Elphick & Harlow, 1997;Wapstra, 2000;Birchard, 2004;Blouin-Demers, Weatherhead & Row, 2004;Watkins & Vraspir, 2006) that can be fitness relevant (Andrews, Mathies & Warner, 2000;Braña & Ji, 2000;Du & Ji, 2003;Andrews, 2008). Thus, it is crucial to understand the relative contribution of phenology and phenotypic plasticity on individual performances and ontogenic trajectories.…”

“…The measurement procedure was similar to that employed byAndrews (2008) and recommendations from Hare, Whitworth & Cree Experimental design used in the present study.…”

Reproductive behavior and development in Spilotes sulphureus (Serpentes: Colubridae) from Ecuador

“…Hatching success is probably related to incubation conditions (Gutzke and Packard 1987, Burger et al 1987, Andrews 2008, Packard and Packard 1988, Werner and Shine 2008.…”

Hormones and Reproductive Cycles in Lizards

“…The opportunities for interesting hormone-reproduction relationships seem compelling given that, across species, there is considerable diversity in the degree of sexual dimorphism and reproductive lifespan (e.g., Karsten et al, 2008). Most chameleons are oviparous although a few give live birth; across oviparous species, clutch sizes can vary tremendously, from 2-4 eggs in smaller species such as leaf chameleons of the genus Brookesia to 40 or more in species such as C. calyptratus Andrews, 2008). Most chameleons are oviparous although a few give live birth; across oviparous species, clutch sizes can vary tremendously, from 2-4 eggs in smaller species such as leaf chameleons of the genus Brookesia to 40 or more in species such as C. calyptratus Andrews, 2008).…”

“…Further, in recent years reproductive behavior has been well-studied for both males and females of several species (e.g., the Madagascan chameleons Furcifer labordi and Furcifer verrucosus (Karsten, Andriamandimbiarisoa, Fox, & Raxworthy, 2009) and the veiled chameleons, Chamaeleo calyptratus (Kelso & Verrell, 2002)), revealing dramatic and in some cases sex-atypical behaviors for lizards such as high sexual aggression in females (dwarf chameleons, Bradypodion pumilum (Stuart-Fox & Whiting, 2005)) and active mate guarding by males of recently mated females in a serially polygynous system (common chameleons, Chameleo chamaeleon (Cuadrado, 2000;). Finally, our understanding of how to maintain chameleons successfully in captivity has improved considerably (e.g., Ferguson et al, 1996;Ferguson, Gehrmann, Chen, Dierenfeld, & Holick, 2002;Andrews, 2008;Karsten, Ferguson, Chen, & Holick, 2009) making them increasingly amenable to laboratory study as well. Finally, our understanding of how to maintain chameleons successfully in captivity has improved considerably (e.g., Ferguson et al, 1996;Ferguson, Gehrmann, Chen, Dierenfeld, & Holick, 2002;Andrews, 2008;Karsten, Ferguson, Chen, & Holick, 2009) making them increasingly amenable to laboratory study as well.…”