Modeling Habitat Selection of the Red-Footed Falcon ( Falco Vespertinus ): A Possible Explanation of Recent Changes in Breeding Range Within Hungary

Abstract

Fehérvári et al.: Modeling habitat selection of the red-footed falcon (Falco vespertinus)-59 - Abstract. Due to a severe population decline and shrinkage of distribution range in the past decades, the red-footed falcon has gained top priority in both worldwide and Hungarian nature conservation. As a facultative colonial breeder, in Hungary, this species predominantly nests in rookeries. The number of rooks (Corvus frugilegus) has also dramatically fallen recently, but population decline did not affect the large scale breeding distribution of this species. In our study we analyzed the presence of red-footed falcons at a colony in the case of current and historical breeding ranges based on landscape scaled habitat variables. We used a potential colony home-range size, estimated from observed home-range sizes in order to determine the scale of influential habitat variables. According to our results, the primary cause of the observed range shift is the urbanization of rooks in definable regions of Hungary. The ratio of forests and open water surfaces within the potential home-range had negative, while the ratio of grasslands had a positive effect on the probability of red-footed falcon presence. None of our models predicted red-footed falcon presence at colonies outside the current breeding range, suggesting that a probable increase in redfooted falcon population numbers will not be accompanied by the expansion of the current breeding range.

Allocating active conservation measures using species distribution models: a case study of red‐footed falcon breeding site management in the Carpathian Basin

“…Red‐footed falcons have suffered from loss of foraging and breeding habitats during the past decades as their foraging habitats have been, while the drastic decrease in rookeries within the Carpathian Basin has had a serious impact on the available nesting sites. In Hungary, the landscape scale distribution of rookeries remained stable, while the density and size of rookeries decreased and their location shifted to human settlements (Fehérvári et al ., ), while similar patterns have been reported from other European countries (Orlowski & Czapulak, ). The reasons of rookery declines can be attributed to a large‐scale persecution in the mid‐80s, resulting in a massive 90% population crash.…”

“…Our modelling approach proved to be successful in describing the landscape scale habitat composition of red‐footed falcon breeding sites in the modelling area. Both RFs and GBMs agreed that natural grasslands and pastures have a considerable impact on the probability of nest site presence, corroborating our previous findings from different spatial scales (Fehérvári et al ., ).…”

“…The reasons of rookery declines can be attributed to a large‐scale persecution in the mid‐80s, resulting in a massive 90% population crash. The obvious consequences for red‐footed falcons was that most of the potential breeding colonies disappeared, causing a shrinkage in distribution range, and a decline in the number of breeding pairs (Fehérvári et al ., and see references therein). Moreover, the ratio of solitary breeders increased, with only 40–50% of the whole population used colonies for breeding at the turn of the century (Bagyura & Palatitz, ).…”

History and current status of Red-footed Falcon population size and conservation activities in Voivodina

“…However, as in Hungary, the frequency of rookeries shifting to urban settlements is increasing (Fehérvári et al 2009), making active conservation measures necessary to maintain the falcon population. We have erected over 350 nest-boxes in various locations, primarily choosing sites that had historic breeding records, or were pin-pointed by landscape scale habitat modelling as suitable breeding sites (Fehérvári et al 2012).…”

Dipteran assemblages in Red-footed Falcon (Falco vespertinus) nest boxes

“…However, due to poisoning of corvids and changes in land use including a decline of animal husbandry, approximately 90% of previously available rookeries either became demolished or moved to urban habitats (Seres & Liker 2015) that are unsuitable for Red-footed Falcons (Fehérvári et al 2009). Consequently, by 2006 the estimated number of Red-footed Falcon pairs was reduced to less than 600.…”