Hard times in the city – attractive nest sites but insufficient food supply lead to low reproduction rates in a bird of prey

Despite the high density of Eurasian kestrel nests in Vienna's urban center, reproductive success is significantly lower compared to less urbanized areas. This study found that while nest sites are abundant and attractive in highly urbanized regions, the availability of prey—particularly rodents—is insufficient, leading to a diet shift towards small birds and higher rates of nest failure, predation, and desertion. The research analyzed breeding parameters over three years, comparing prey abundance with dietary data along an urbanization gradient. Results suggest that kestrels are drawn to urban habitats due to the availability of nesting cavities but face ecological challenges, such as reduced food supply and increased predation risks, which may trap them in suboptimal environments.

Sumasgutner, P., Nemeth, E., Tebb, G., Krenn, H. W., & Gamauf, A. (2014). Hard times in the city – attractive nest sites but insufficient food supply lead to low reproduction rates in a bird of prey. Frontiers in Zoology, 11(1), 48. https://doi.org/10.1186/1742-9994-11-48