Effects of nest boxes on the most important population of red-footed Falcon Falco vespertinus in Italy.
The red-footed falcon is a near threatened species, which breeds mainly in agricultural landscapes, typically nesting in empty corvid nests on trees. In Europe, this species is declining due to habitat degradation and agriculture intensification. The aim of our study was to determine the reproductive success and the increase in the number of nesting pairs after the installation of nest boxes. This study took place in the Italian province of Parma, the southernmost part of the red-footed falcon's breeding range. Nest boxes were provided in four locations, where falcons were already breeding in corvid nests, to assess if this action could increase the falcon population and breeding success in the study area. After the deployment of 117 nest boxes from 2010 to 2018 the Parma population increased from 25 to 82 pairs, occupying up to 50% of available boxes in 2018. The breeding success remained unvaried over the study period with an average of 2.06 and 2.37 chicks fledged per pair in corvid nests and nest boxes respectively. It also did not differ between the two nest categories. These results could indicate that a lack of suitable nesting sites is a major limiting factor for the falcon population in the Parma province rather than lack of food.