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
Common miner long, dug into an earth bank or sand dune. Common miner The common miner ("Geositta cunicularia") is a passerine bird of South America, belonging to the ovenbird family. It is a ground-dwelling bird which feeds on insects and seeds. It has about 9 different subspecies, some of which may be better treated as separate species. It is 14 to 16 cm long with a fairly long, slightly downcurved bill. The plumage varies geographically but is basically brown above and pale below with a streaked breast, pale stripe over the eye, dark edge to the ear-coverts and pale rufous bar across