Nest site selection in a southern and northern population of the velvet gecko (Amalosia lesueurii). (December 2021)

• Record Type: Journal Article
• Authors: Cuartas-Villa, Santiago; Webb, Jonathan K.
• Is Part Of: Journal of thermal biology. Volume 102(2021)
• Publication Date: 2021-12
• Subjects: Nest-site selection -- Reptile -- Nest temperature -- Incubation -- Heatwaves; Thermobiology -- Periodicals; Temperature -- Periodicals; Biology -- Periodicals; Thermobiologie -- Périodiques; Thermobiology; Periodicals; 571.46
• DOI: 10.1016/j.jtherbio.2021.103121
• Languages: English
• ISSNs: 0306-4565

Abstract

Abstract: In many oviparous reptiles, thermal conditions inside nests influence phenotypic traits of hatchlings that are linked to survival. Maternal nest-site selection can therefore have long-term implications for offspring and maternal fitness. We studied nest-site selection in a nocturnal lizard ( Amalosia lesueurii ) from south eastern Australia. Females of this species lay their eggs communally inside rock crevices, and previous studies have shown that maximum daily nest temperatures are positively correlated with maximum daily air temperatures. The incubation period extends for up to 100 d, so during hot summers, embryos may be exposed to stressful thermal conditions. Potentially, mothers could buffer their eggs from thermal extremes via careful selection of nest sites. To evaluate this, we studied nest site selection in a southern population (Morton) and a northern population (Yengo) that experience mild and hot summers respectively. In the field, we measured the physical characteristics, orientation, canopy cover and incident radiation load, and thermal regimes of nest sites and randomly available crevices during one of the hottest Australian summers on record (2018–2019). We found strong inter population differences in the degree of canopy cover and solar radiation loads above nest sites. Nest sites from Morton were more open, and received higher radiation loads, than nest sites from Yengo. Mean nest temperatures were similar in Morton and Yengo, but nests from Yengo experienced higher daily temperatures than those from Morton. During heatwaves, temperatures in some nests exceeded the species critical thermal maximum (39.9 °C) for several hours each day. Our results show that females can adjust nest-site choice to match local environments, but future research is necessary to clarify whether exposure to high temperatures influences hatching success or offspring phenotypes in this species. Highlights: Velvet gecko ( Amalosia lesueurii ) females adjust nest-site choice to suit local environments. Some nests temperatures exceeding species' CTmax during heatwaves. Inter population differences in canopy cover and solar radiation above nest sites. Thermal regimes measured during one of the hottest Australian summers on record. There is strong positive correlation between air and nest temperatures.