Several studies have shown that hybridization can be a creative process by acting as a conduit for the spread of adaptive traits between species, but few provide the mechanism that favours this spread. In the hybrid zone between the golden- (Manacus vitellinus) and white-collared (Manacus candei) manakins, sexual selection drives the introgression of golden/yellow plumage into the white species...

The polymorphism of microphthalmia-associated transcription factor (MITF) and tyrosinase (TYR) genes have been proposed to play a vital role in coat colour genesis in mammals, but their role remains ambiguous in geese at best. Here, we cloned and sequenced 1,397 bp coding region of MITF gene and a 588 bp fragment of TYR exon 1 for polymorphism analysis among 157 domestic geese showing three typ...

The Brazilian tanager, Ramphocelus bresilius is an endemic species from Brazil that is sexually dimorphic in adult plumage. Young males are similar to adult and young females until their second year. Adults and young females are not distinguishable in plumage. We tested whether iris colour can be used to separate adult females from immature females. We used for the first time the molecular sexi...

Reproductive isolation can be initiated by changes in one or a few key traits that prevent random mating among individuals in a population. During the early stages of speciation, when isolation is often incomplete, there will be a heterogeneous pattern of differentiation across regions of the genome between diverging populations, with loci controlling these key traits appearing the most distinc...

Theory suggests that traits under positive selection may introgress asymmetrically across a hybrid zone, potentially driven by sexual selection. Two subspecies of the red-backed fairy-wren (Malurus melanocephalus) differ primarily in a sexual signal used in mate choice-red versus orange male back plumage colour-but phylogeographic analyses suggest asymmetrical introgression of red plumage into ...

The identification and sequencing of a gene affecting melanin production in the bananaquit, a bird species notable for its polymorphic plumage colour, paves the way for much greater understanding of the evolution of plumage patterns in birds, and the developmental modulations involved in producing new patterns.

Variation in wavelength sensitivity among subspecies is unknown among vertebrates. The parrot Platycercus elegans has extreme plumage variation between subspecies ranging from pale yellow to crimson which, with differences in background colour and light environment between subspecies, makes it a good candidate for the evolution of within-species differences in vision. We report differences in v...

On current knowledge, it has not been possible to determine the sex of Blue-fronted Amazons (Amazona aestiva) in the hand, as males and females were thought not to differ in the colour of plumage or size. We used discriminant function analysis to develop equations for determining the sex of Blue-fronted Amazons using in-hand measurements. We took sevenmeasurements of size and onemeasure of plum...

There is growing evidence that post-copulatory sexual selection, mediated by sperm competition, influences the evolution of sperm phenotypes. Evidence for pre-copulatory sexual selection effects on sperm traits, on the other hand, is rather scarce. A recent paper on the pied flycatcher, Ficedula hypoleuca, reported phenotypic associations between sperm length and two sexually selected male trai...

It has been hypothesized that white plumage facilitates flock formation in Ardeidae. We conducted four experiments using decoys to test factors involved in attracting wading birds to a specific pond. The first three experiments tested the effects of plumage colouration, flock size, and species-specific decoys on flock formation. The fourth experiment examined intraspecific differences in flock ...