In most animals, members of one sex compete more intensely for mates than members of
the other sex, and show a greater development of secondary sexual traits. The relative …

Using optimality perspectives is now regarded as an essential way of analysing and
understanding adaptations and behavioural strategies in bird migration. Optimization …

Bright colors, enlarged fins, feather plumes, song, horns, antlers, and tusks are often highly
sex dimorphic. Why have males in many animals evolved more conspicuous ornaments …

One hundred years after Darwin considered how sexual selection shapes the behavioral
and morphological characteristics of males for acquiring mates, Parker realized that sexual …

(Invited Article) Abstract Sexual size dimorphism (SSD) is widespread and variable among
animals. According to the differential equilibrium model, SSD in a given species is expected …

Protandry, the earlier arrival of males to breeding areas than females, is a common pattern
of sex‐biased timing in many animal taxa (eg some insects, fish, amphibians, reptiles, birds …

Studies examining interspecific differences in sexual size dimorphism (SSD) typically
assume that the degree of sexual differences in body size is invariable within species. This …

Arrival times for migratory animals can be viewed as the result of an optimization process of
costs and benefits of early arrival, and when the cost and benefit functions of early arrival …

A prominent interspecific pattern of sexual size dimorphism (SSD) is Rensch's rule,
according to which male body size is more variable or evolutionarily divergent than female …

Summary 1 In migratory birds males tend to arrive first on breeding grounds, except in sex‐
role reversed species. The two most common explanations are the rank advantage …