Students of behavior have neglected yawning. It is rarely mentioned in animal behavior texts, and even books that would seem to be particularly relevant, such as Hinde's (1972) Non Verbal Communication, do not include yawning in the index. In physiology the standard texts such as Starlings Human Physiology (Davson & Eggleton, 1962) or the revised Johns Hopkins Atlas of Human Functional Anatomy ...

Investigations of communication networks in animals have focused primarily on determining whether animals extract information from peripheral contests (eavesdropping) or respond to the presence of bystanders (audience effect). The possibility that an animal’s response to being watched might be context dependent, however, has been explored in far less detail. This study investigated the influenc...

Carotenoid pigments are responsible for many examples of sexually attractive red, orange, and yellow coloration in animals and play an important role in antioxidant and immune defenses. Because vertebrates cannot synthesize carotenoids, limited dietary availability may impose a trade-off between maintaining ornamental coloration and health. We used an experimental approach to test the carotenoi...

Behavioural laterality (e.g., during social interactions) is often observed at the individual level in lower vertebrates such as fish, whereas population-level laterality is observed in many higher vertebrates. Population-level laterality can be explained mainly by internal factors (e.g., cerebral lateralization), whereas little is known about the behavioural mechanisms underlying individual-le...