Dunnock relatively lower success for females. In times of scarcity, female territories expand to accommodate the lack of resources, causing males to have a more difficult time monopolizing females. Hence, females gain a reproductive advantage over males in this case. The dunnock possesses variable mating systems. Females are often polyandrous, breeding with two or more males at once, which is quite rare among birds. This multiple mating system leads to the development of sperm competition amongst the male suitors. DNA fingerprinting has shown that chicks within a brood often have different fathers, depending on the success of the males at monopolising
International Bird Rescue International Bird Rescue Research Center, the organization cares for an estimated 5,000 birds annually at two rehabilitation centers, the Los Angeles Oiled Bird Care and Education Center and the San Francisco Bay Oiled Wildlife Care and Education Center, that also serve as primary care facilities for oiled birds in the event of a spill in California. Common bird species treated include brown pelicans, common murres, western grebes, pacific loons, and a variety of gulls, herons, and other waterfowl. International Bird Rescue is a member of the Oiled Wildlife Care Network (OWCN), which is managed by the UC Davis School of