Temporal variation in maternal nest choice and its consequences for lizard embryos

Microhabitat choice of nest sites is an important maternal effect that
influences the survival and development of embryos in oviparous species.
Embryos of many species display a high degree of plasticity in response to
developmental environments, which places maternal nesting behavior under
strong selective pressure, particularly in temporally-changing
environments. Nesting behavior varies widely across taxa that exhibit
diverse reproductive strategies. The brown anole (Anolis sagrei), for
example, lays one egg every 7-10 days across an extended reproductive
season from April to October. This aspect of their reproduction provides
an opportunity to examine temporal shifts in nesting behavior and its
consequences on egg survival and offspring development under
seasonally-changing climatic conditions. We conducted a two-part study to
quantify temporal variation in maternal nesting behavior and its effect on
development of A. sagrei embryos. First, we measured nest
microenvironments over the nesting season. Second, we “planted” eggs
across the landscape at our field site to examine the influence of nest
conditions on egg survival and hatchling phenotypes. We also incubated
eggs inside chambers in the field to decouple effects of nest moisture
from those of other environmental variables (e.g., temperature).Females
chose nest sites with higher moisture and lower temperatures relative to
what was generally available across the landscape during the nesting
season. In addition, eggs exposed to relatively cool temperatures had
higher hatching success, and high nest moisture increased egg survival and
body condition of hatchlings. Overall, we provide evidence in the field
that maternal nesting behavior facilitates offspring survival.