Dominance, Coloration, and Social and Sexual Behavior in Male Drills Mandrillus leucophaeus
Sexual selection has driven the evolution and elaboration of a wide variety of displays and ornaments in male nonhuman primates, including capes, cheek flanges, and sexual coloration. Among the most sexually dimorphic of all primates is the drill (Mandrillus leucophaeus), the males of which can be 3 times the mass of females, possess large canines, […]
Blue tits are ultraviolet tits
The blue tit (Parus caeruleus) has been classified as sexually monochromatic. This classification is based on human colour perception yet, unlike humans, most birds have four spectrally distinct classes of cone and are visually sensitive to wavelengths in the near-ultraviolet (300 to 400 nm). Reflectance spectrophotometry reveals that blue tit plumage shows considerable reflection of […]
Female kestrels gain reproductive success by choosing brightly ornamented males
Female choice with respect to male coloration, and its consequences for fitness, were studied in the European kestrel, Falco tinnunculus. In an aviary experiment, females preferred to approach bright males. Under natural conditions, bright males spent more of their time hunting than dull males. Females mated with bright males produced more offspring than those mated […]
Does the environmental context of a signalling male influence his attractiveness?
How sexually selected male signals and female sensory systems have evolved so that females can continue to detect and discriminate between potential mates in the face of environmental noise and changes in signaller density has been well studied for acoustic signals. Far less is known about visual signals. We examined the influence of the local […]
Female preference and fitness benefits of mate choice in a species with dissociated sperm transfer
Female mate preference can have important fitness consequences for females through direct or indirect benefits of mate choice. However, the existence and benefits of mate choice in species that perform dissociated sperm transfer is largely unknown. In the springtail Orchesella cincta, receptive females locate and take up spermatophores deposited in the litter layer by males, […]
Female influences on pair formation, reproduction and male stress responses in a monogamous cavy (Galea monasteriensis)
We examined the possible existence of, and female contributions to, pair bonds, as well as the relation of social preference to mating selectivity, in a recently identified wild guinea pig, the Muenster yellow-toothed cavy (Galea monasteriensis). In Experiment 1, females housed for ~ 20 days in an apparatus in which they could choose to approach and interact […]
Male monkeys fight in between-group conflicts as protective parents and reluctant recruits
In many social species, group members cooperate to defend a communal home range. Fighting in between-group conflicts carries an opportunity cost, a risk of injury or death, and the possibility of exploitation by free-riding group members. As a result, it is rare that all group members fight in a given between-group conflict, and individual participation […]