Sexual signals in different animals are expected to be dimorphic when both sexes signal, but cases of monomorphism are known to occur, and we lack a clear understanding about the factors that modulate the level of sexual ...

In anurans, production of advertisement calls in sexual contexts is predominantly an attribute of males. Female calls occur in a small proportion of species, and these signals typically differ from those of males. The ...

Life history predicts that in sexually dimorphic species in which males are the larger sex, males should reach sexual maturity later than females (or vice versa if females are the larger sex). The corresponding prediction ...

The extent to which males and females of monomorphic species differ from each other is still an ecological and evolutionary puzzle. In these species it has been proposed that slight differences in selection pressures can ...

Sexes can differ in features associated with differential reproduction, which can be used during courtship or aggressive encounters. Some traits tend to evolve independently between sexes and emerge as sexually dimorphic ...

Parrots (Psittacidae Family) are one of the most colorful groups of birds in the world, their colors produced both structurally and via unusual pigments (psittacofulvins). Most species are considered to be monogamous, and ...

Understanding sex differences in foraging behaviour has important implications for breeding biology and population ecology. This requires the evaluation of segregation throughout the annual cycle, including the non-breeding ...

Long-term behavioral studies require the permanent identification of individuals. The need for individual identification is even more crucial for sexually monomorphic species since not even the sexes can be differentiated ...

Sexual dimorphism in birds may express itself as differences in body size, plumage, color and/or behavior. Many species are monomorphic in color, which makes sex determination difficult in the field. In order to develop a ...