The Danish Peregrine Falcon population is increasing

• Main Authors: Andreasen, Niels Peter, Falk, Knud, Møller, Søren
• Format: Conference Object
• Language: English
• Published: 2017
• Subjects: Vandrefalk; Danmark; Peregrine Falcon; Denmark; Falco peregrinus; peregrine falcon; vandrefalk
• Online Access: https://forskning.ruc.dk/da/publications/324a262d-977d-41c9-8381-4cba1ab91e44; https://hdl.handle.net/1800/324a262d-977d-41c9-8381-4cba1ab91e44; http://www.peregrinus.pl/files/peregrine_conference_2017/4th_peregrine_Conference_Abstact_book_web.pdf

Denmark being a country with only a few suitable steep nesting cliffs has only harbored a small population of peregrine falcons (Falco peregrinus) in historic time. In the previous century the population gradually declined due to persecution, egg and young collection, and pollution. The last breeding attempt in the 20th century occurred in 1972 at Møns K lint in southeastern Denmark. No new breeding attempts were recorded in Denmark until 2001 where a male peregrine from southern Sweden and a female from northern Germany paired up at the location mentioned above. Since then the Danish peregrine population has gradually increased – most rapidly since 2012 – to 19 known territorial pairs in 2016; some of them breeding on man-made structures (nest boxes at bridges and power plants). In this poster, we present detailed information on the reestablishment of the peregrine falcon in Denmark: origin and dispersal, reproduction, and eggshell thinning. Color banding programs in the neighboring countries (and since 2009 in Denmark) have in some cases made it possible to determine the origin of breeding peregrines. Peregrines originating from neighboring countries have in eight cases been observed breeding in Demark: 3 from Sweden, 4 from Germany and 1 from Poland. Similarly, peregrines banded in Danish eyries have been observed as territorial or breeding in Sweden (2 cases) or at other locations in Denmark (5 cases). The reproduction measured as number of ‘young per successful pair’ (reaching ringing age) and ‘young per occupied territory’ (“productivity”) is on average 2.2 and 1.3, respectively, for the entire period 2001-2016. The productivity of Danish peregrines is thus well above the critical limit (1.0 according to USFWS), where concerns may be raised. Not much is known about contaminant loads in Danish peregrines. One of the eggs from the breeding attempt in 1972 was analyzed for DDT and PCB and the result showed very high values. The eggs from the failed breeding attempt in 2001 were also collected but have not ...