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
European Bird Census Council forces behind population changes and use common bird indicators as a proxy for environmental health, and thus inform policy. Monitoring data is published as the European Breeding Birds Atlas, the second of which (EBBA2) is currently in preparation. The data collected as part of the PECBMS and EBBA2 programmes is also distributed on the EBCC-run portal, EuroBirdPortal, as well as through the Global Biodiversity Information Facility (GBIF). The EBCC run a conference every three years, devoted to ornithological monitoring, conservation and research in Europe and abroad. The organisation also publishes the Journal of the European Bird Census Council, entitled "Bird