The aim of this review is to consider the potential benefits that females may gain from mating
more than once in a single reproductive cycle. The relationship between non-genetic and …

The aim of this review is to consider the potential mechanisms birds may use to manipulate
the sex of their progeny, and the possible role played by maternal hormones. Over the past …

Molecular sexing is an attractive means to determine the sex of sexually monomorphic birds,
eg chicks of most species. A universal approach for molecular sexing of birds would require …

Recent decades have witnessed an explosion of theoretical and empirical studies of sex
allocation, transforming how we understand the allocation of resources to male and female …

The avian W chromosome shares many features with the mammalian Y chromosome: it is
small, mostly heterochromatic, and filled with large repetitive arrays. No gene has so far …

When the relative fitness of male and female offspring varies with environmental conditions,
evolutionary theory predicts that parents should adjust the sex of their offspring accordingly …

In spite of strong evidence for viability–based sexual selection and sex ratio adjustments, the
blue tit, Parus caeruleus, is regarded as nearly sexually monomorphic and no epigamic …

Brilliant blue and violet structural colours are common plumage ornaments in birds, but their
signalling functions are poorly understood. This may be because birds also communicate in …

When the relative fitness of sons and daughters differs, sex-allocation theory predicts that it
would be adaptive for individuals to adjust their investment in different sexes of offspring …

As evidenced by the articles in this volume, a recent increase in interest in the mating
systems of poikilothermic vertebrates has focused primarily on fishes, a few amphibians, and …