A study coordinated by the Doñana Biological Station (EBD-CSIC) and the Pyrenean Institute of Ecology (IPE-CSIC) shows that the physical attractiveness of birds does not determine their reproductive success.
The results, contrary to expectations, demonstrated that the density of mates and competitors did not influence whether the most attractive males had more or fewer descendants .

Bats are assumed not to use vision for communication, despite recent evidence of their capacity for color vision. The possibility that bats use color traits as signals has thus been overlooked. Some tent-roosting bats have a potential for visual signaling because they exhibit bright yellow skin, a trait that in birds often acts as a sexual signal. The authors searched for evidence of sexual dichromatism in the yellow bare skin of Honduran white bats Ectophylla alba.

Sexual selection can drive the evolution of phenotypic traits because of female preferences for exaggerated trait expression in males. Sexual selection can also lead to the evolutionary loss of traits, a process to which female preferences for diminished male trait expression are hypothesized to contribute. However, empirical evidence of female preferences for diminished male traits is virtually lacking. Eurasian nuthatches Sitta europaea provide an opportunity to test this possibility, as a...

Colours that underlie animal pigmentation can either be permanent or renewable in the short term. Here the discovery of a conspicuous salmon-pink colouration in the base of bustard feathers, never been reported because of its extraordinarily brief expression, is described.

One paradoxical finding in some mammals is the presence of male–male intrasexual competition in the absence of sexual size dimorphism. It has been a major goal of evolutionary biologists for over a century to understand why some species in which large males can monopolize multiple mates while excluding smaller competitors, exhibit little or no sexual dimorphism. In this paper three of the main hypotheses that have been proposed to explain this conundrum are examined using as study case...