Variation in communicative complexity has been conceptually and empirically attributed to
social complexity, with animals living in more complex social environments exhibiting more …

Primates are noted for their varied and complex pelage and bare skin coloration but the
significance of this diverse coloration remains opaque. Using new updated information …

This comprehensive introductory text integrates evolutionary, ecological, and demographic
perspectives with new results from field studies and contemporary noninvasive molecular …

Sexual dimorphism in ornamentation in primates may have been sexually selected as
signals of rank and dominance to males or by augmenting attractiveness to females. While …

External eye appearance across primate species is diverse in shape and colouration, yet we
still lack an explanation for the drivers of such diversity. Here we quantify substantial …

Animal visual signals have the potential to act as an isolating barrier to prevent
interbreeding of populations through a role in species recognition. Within communities of …

Facial hair is a prominent secondary sexual trait, particularly given the importance of the
face in interpersonal communication. Bizarrely by animal standards, men expend …

Chordates comprise lampreys, hagfishes, jawed fishes, and tetrapods, plus a variety of more
unfamiliar and crucially important non-vertebrate animal lineages, such as lancelets and sea …

Chimpanzee (Pan troglodytes) sclera appear much darker than the white sclera of human
eyes, to such a degree that the direction of chimpanzee gaze may be concealed from …

Males must partition their limited reproductive investments between traits that promote
access to females (sexual ornaments and weapons) and traits that enhance fertilization …