The mechanisms underlying evolutionary changes in sexual dimorphism have long been of
interest to biologists. A striking gradient in sexual dichromatism exists among songbirds in …

Sexual dimorphisms in weaponry and aggression are common in species in which one sex
(usually males) competes for access to mates or resources necessary for reproduction …

Some Australian native birds become childhood sweethearts and court for years before they
get'married'. Others divorce because of personality clashes and different skill levels. Many …

Elongated tails are elaborate plumage traits possessed by a variety of bird species. Sexual
selection has long been the dominant hypothesis for explaining why certain species …

Many species of insectivorous birds have contrasting plumage patches that are often
displayed during foraging. Although such displays are widely hypothesized to flush potential …

Male and female American goldfinches (Spinus tristis) express condition‐dependent
carotenoid‐based plumage and bill coloration. Plumage color is relatively static, as …

Selection arising from social competition over non-mating resources, ie resources that do
not directly and immediately affect mating success, offers a powerful alternative to sexual …

Size‐assortative mating is a nonrandom association of body size between members of
mating pairs and is expected to be common in species with mutual preferences for body …

Cassowaries (Casuarius) possess a cranial casque, sheathed by keratin and composed of
modified cranial bones. We combine data and hypotheses on three areas of cassowary …

Status signals are linked to fighting ability and enable competitors to gain access to
resources without risking injury in aggressive combat. The relationship between …