Avian eggs contain substantial amounts of maternal hormones and so provide an excellent
model to study hormone-mediated maternal effects. We review this new and rapidly evolving …

The aim of this review is to consider the potential mechanisms birds may use to manipulate
the sex of their progeny, and the possible role played by maternal hormones. Over the past …

Why do males and females frequently differ so markedly in body size and morphology? Sex,
Size, and Gender Roles is the first book to investigate the genetic, developmental, and …

In species where offspring fitness is sex-specifically influenced by maternal reproductive
condition, sex allocation theory predicts that poor-quality mothers should invest in the …

Birds and mammals are sometimes viewed as black sheep, notorious for their failure to pay
attention to the elegance of adaptive sex ratio theory to the same extent as other animals …

The question of why maternal stress influences offspring phenotype is of significant interest
to evolutionary physiologists. Although embryonic exposure to maternally derived …

Sex ratio theory attempts to explain variation at all levels (species, population, individual,
brood) in the proportion of offspring that are male (the sex ratio). In many cases this work has …

Summary 1 Individual variation in the trade‐off between self‐maintenance and offspring
quality was assessed in tree swallows, Tachycineta bicolor, by manipulating reproductive …

Egg formation is a demanding process both in terms of energy and nutrient requirements.
Birds must not only collect specific nutrients for egg formation, but must do so over a brief …

Recent studies have shown that some species of birds have a remarkable degree of control
over the sex ratio of offspring they produce. However, the mechanism by which they achieve …