We exposed females of a highly placentotrophic viviparous scincid lizard (P
seudemoia pagenstecheri) to various environmental factors during pregnancy,
and quantified the effects of these treatments on their offspring. The cle
ar result was that the phenotypes of neonatal lizards can be substantially
modified by the environment that their mother experiences during gestation.
Restricting prey availability to the females reduced the size of their off
spring. Limiting the females' basking opportunities delayed their seasonal
timing of parturition, and modified body proportions (tail length relative
to snout-vent length) of the neonates. More surprisingly, female lizards th
at were regularly exposed to the scent of sympatric lizard-eating snakes ga
ve birth to offspring that were heavier, had unusually long tails relative
to body length, and were highly sensitive to the odour of those snakes las
measured by tongue-flick responses). The neonates' antipredator responses w
ere also modified by the experimental treatment to which their mother was e
xposed. The modifications in body mass, tail length and response to snake s
cent plausibly reduce the offspring's vulnerability to predatory snakes, an
d hence may constitute adaptive maternal manipulations of the neonatal phen
otype.