Is the ultraviolet waveband a special communication channel in avian mate choice?

There is growing evidence that ultraviolet (UV) wavelengths play an important role in avian mate choice. One of the first experiments to support this idea showed that female zebra finches (Taeniopygia guttata) prefer UV-reflecting males to males whose ultraviolet reflection has been removed. The effect was very strong despite little or no UV reflection from […]

Coloured patches influence pairing rate in King Penguins

Ever since Darwin’s (1871) original description of sexual selection, evolutionary biologists have been intrigued by colourful attributes of animals that appear to be ornamental, without offering direct visible benefits to animals. Nevertheless, the potential biological utility of ornaments was only recently tested, perhaps because traits like the Peacock’s Pavo cristatus tail offer no direct, visible […]

Signaling stress? An analysis of phaeomelanin-based plumage color and individual corticosterone levels at two temporal scales in North American barn swallows, Hirundo rustica erythrogaster

Sexually selected traits confer greater reproductive benefits to individuals with more elaborate forms of the signal. However, whether these signals convey reliable information about the physiology underlying trait development remains unknown in many species. The steroid hormone corticosterone (CORT) mediates important physiological and behavioral processes during the vertebrate stress response, and CORT secretion itself can […]