Blue Tits Cyanistes Caeruleus And Great Tits Parus Major As Urban Habitat Breeders

Abstract The Great Tit Parus major and the Blue Tit Cyanistes caeruleus are the only Western Palearctic Parids that maintain numerous urban populations as well as forest populations. Because of their evolutionary history both these species are best adapted to different types of deciduous and mixed forests. Ecological conditions in cities are different from those dominating in forests, especially in such aspects as: habitat fragmentation, tree species composition, microclimate, human activity, predators and food conditions. The tits breeding in cities start laying eggs earlier in the season, lay smaller clutches and fledge fewer fledglings of lower quality. Yet urban populations are often relatively stable in numbers. This may result from the fact that survival of winter is higher in cities due to increased availability of food and milder weather.