Loss of nesting sites
Probably one of the most important limiting factors for the breeding population is the number of available aggregated nests in suitable habitats. As Red-footed falcons primarily use rookeries for colonial breeding throughout their breeding range, the threats that afftect rook colonies also apply to red-footed falcons. For example, in Hungary both the number of traditional, high-density red-footed falcon colonies and the mean number of pairs per colony has decreased significantly in the past few decades (Bagyura & Palatitz 2004). These changes can partially be attributed to the collapse of the rook population during the 1980-2006 period (from 320 000 to 23 000 pairs). This population crash is attributed to the use of targeted poisoning scheme for Corvids, widely implemented in the 80’s and early 90’s, in Hungary. Therefore, the number of rookeries suitable for red-footed falcon nesting drastically declined resulting in the contraction of breeding range in Hungary.
Common direct threats to rookeries in Hungary and other range-states are illegal logging, deliberate destruction, and disturbance of nests. Moreover, in some range states rooks are officialy a hunted species (Romania), or are considered as pests (Ukraine) and therefore all direct persecution activities (primarily shooting and disturbance) are allowed.
Even if rook populations in some range states are stable (BirdLife International 2009) certain populations of this species have moved to settlements. This shift in habitat selection of rooks may affect the red-footed falcon (Fehérvári et al. 2009) who may not favour it.