Persecution by humans affects nest‐site selection of Hooded Crows: a comparison of an urban and two rural areas

The Hooded Crow, a bird species that once occurred only in agricultural areas, has colonized urban environments in the last 50–100 years in Europe. Apart from higher food availability, safer nesting sites, better thermoregulation and lower predation in cities, persecution through hunting, trapping or poisoning by humans in rural areas is an important but rarely studied factor in this process. We compared nest‐site selection by Hooded Crows in one urban and two rural areas, one of which had active crow control (high persecution) by regular trapping and hunting, whereas the other had sporadic low persecution. Based on data collected from 285 nests over 3 years, we found that nesting density was lower, and nests were farther from nearest neighbours, roads and grasslands in the high‐persecution rural site than in the urban site or the low‐persecution rural site. In the low‐persecution site, nesting density was intermediate, and nests were close to nearest neighbours, roads and grasslands. In the urban site, nesting density was high, nearest neighbours were close and distance to roads was negligible, whereas distance to grassland was intermediate. Crows tended to use tree lines or groups in each of the three sites, while the tree species used for nesting were usually those that had the highest availability locally. Our results not only reveal important differences in nest‐site selection between urban and rural areas but also draw attention to relevant differences between rural habitats because persecution fundamentally affected nest‐site selection in rural areas. Our study indirectly supports the view that persecution in rural areas may have been an important factor in the colonization of urban environments by the Hooded Crow.