Juvenile growth and survival under dietary restriction: Are males and females equal?

Abstract

The effects of food availability on life-history traits may be direct or delayed and may vary between the sexes. We evaluated the effects of dietary restriction early in life on growth and survival of male and female juveniles in the common lizard (Lacerta vivipara) and surveyed the literature on sex-specific sensitivity to the environment in vertebrates. Juvenile lizards were reared in the laboratory during one month following birth under full feeding or under dietary restriction. They were then released in two outdoor enclosures, where we compared growth and survival between treatments during one year. Low food availability early in life led to lower body growth in a direct, but not delayed, manner. The absence of compensatory growth in juveniles that experienced dietary restriction might be explained by their reduced competitiveness. Dietary restriction had a strongly negative, delayed effect on survival up to the age of one year that was mediated by selection against smaller individuals. Effects of dietary restriction were not sex-specific, as expected from the similar energetic requirements of male and female juveniles. Hence, food availability has long-lasting consequences on life-history traits that might influence population dynamics in this species. Copyright © Oikos 2005.