5 torthaí
Whereas humans have three types of cone photoreceptor, birds have four types of single cones and, unlike humans, are sensitive to ultraviolet light (UV, 320-400 nm). Most birds are thought to have either a violet-sensitive single cone that has some sensitivity to UV wavelengths (for example, many
We report on the oldest European songbird (Passeriformes), from the early Oligocene (30-34 million years ago) of Frauenweiler in Germany. The specimen represents the earliest associated remains of an early Tertiary passerine described so far. It ties the first appearance of Passeriformes in Europe
The capacity for vocal recognition of individual conspecifics is well documented in many species, but the perceptual mechanisms that underlie this ability in oscines are less well understood. Using operant conditioning, we trained three groups of European starlings on a baseline task to discriminate
Studies on singing behavior in Oscine focus essentially on males and are carried out during the breeding season. Singing in females appears rare and is not well documented. However, females of several species can produce a complex song. Does this lack of data correspond to a real difference in males
Many behavioral effects of testosterone on hypothalamic and limbic brain areas are mediated by the action, at the cellular level, of estrogens derived from local testosterone aromatization. Aromatase activity and cells containing the aromatase protein and mRNA have accordingly been identified in the