Impact of Nest Predators on Migratory Woodpigeons Columba palumbus in Central Europe — Breeding Densities and Nesting Success in Urban Versus Natural Habitats

Abstract

Abstract. The Woodpigeon Columba palumbus is a species generally increasing in numbers in most of its populations, including the urban population, which, two centuries after its emergence, is still expanding across the European Lowland. New for the species is a tendency to form dense breeding aggregations in suitable urban parks, with a corresponding slower increase in some other towns. This trend was driven by the presence of important nest predators, mostly Hooded Crows Corvus corone. Another factor involved was access to open farmland within the economic range of feeding flights. Nesting success (1st brood) in urban habitats free of important predators was up to 50–77% but it fell to only 3–7% when predators appeared. Consequently, some urban populations of the Woodpigeon went into a phase of decline. In the farmland and secondary woods, the nesting success was also variable, ranging between 12 and 42% for unknown reasons. Safe urban populations produced 4–5 times more offspring per pair per season, yet their expansion was rather slow. Therefore, the urban overproduction may contribute to an increase in the total species abundance, owing to (deduced) overspill of recruits to the poorly reproducing subpopulation in the countryside. Alongside other factors such as amelioration of winter conditions and changes in agriculture, this would contribute to the documented growth of the whole population of the species. The shortage of firm data on the pristine breeding success (from extensive natural forests) remains the main obstacle to better understand the population dynamics of this migratory species.