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
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