Dunnock two or three adjacent female territories overlap one male territory, and so polygyny is favored, with the male monopolising several females. Polygynandry also exists, in which two males jointly defend a territory containing several females. Polyandry, though, is the most common mating system of dunnocks found in nature. Depending on the population, males generally have the best reproductive success in polygynous populations, while females have the advantage during polyandry. Studies have illustrated the fluidity of dunnock mating systems. When given food in abundance, female territory size is reduced drastically. Consequently, males can more easily monopolise the females. Thus, the mating
Acrocephalus (bird) Acrocephalus (bird) The Acrocephalus warblers are small, insectivorous passerine birds belonging to the genus "Acrocephalus". Formerly in the paraphyletic Old World warbler assemblage, they are now separated as the namesake of the marsh and tree warbler family Acrocephalidae. They are sometimes called marsh warblers or reed warblers, but this invites confusion with marsh warbler and reed warbler proper, especially in North America, where it is common to use lower case for bird species. These are rather drab brownish warblers usually associated with marshes or other wetlands. Some are streaked, others plain. Many species breeding in temperate regions are migratory. This