Natural and anthropogenic influences on the population structure of white‐tailed eagles in the Carpathian Basin and central Europe

Abstract

European populations of the white‐tailed eagle Haliaeetus albicilla suffered a drastic decline during the 20th century. In many countries, only a few dozen breeding pairs survived or the species disappeared completely. By today, the populations have recovered, naturally or through restocking (e.g. in Scotland or the Czech Republic). In the Carpathian Basin, which is now a stronghold in southern Europe for the species in the southern part of the distribution range with more than 500 breeding pairs, only about 50 pairs survived the bottleneck. This region provides important wintering places for individuals arriving from different regions of Eurasia. In the present study, we investigated 249 DNA samples from several European countries, using 11 microsatellites and mitochondrial control region sequences (499 bp), to answer two main questions: 1) did the Carpathian Basin population recover through local population expansion or is there a significant gene flow from more distant populations as well? 2) Does the Czech population show signs in its genetic structure of the restocking with birds of unknown origin? Our microsatellite data yielded three genetically separate lineages within Europe: northern, central and southern, the latter being present exclusively in the Carpathian Basin. Sequencing of mitochondrial DNA revealed that there is one haplotype (B12) which is not only exclusive to the Carpathian Basin but it is frequent in this population. Our results suggest that in accordance with the presumably philopatric behaviour of the species, recovery of the Carpathian Basin population was mainly local, but some of the wintering birds coming from the northern and central populations contributed to its genetic composition as well. We detected considerably higher proportions of northern birds within the Czech Republic compared to the neighbouring areas, making it likely that parents of the reintroduced birds came from northern populations.

Genetic structure confirms female-biased natal dispersal in the White-tailed Eagle population of the Carpathian Basin

“…they start breeding relatively close to their natal area), as supported by both ringing data (Helander 2003, Helander & Stjernberg 2003, StruweJuhl & Grünkorn 2007, Whitfield et al 2009a and genetic structure of their wild populations (Hailer et al 2007, Honnen et al 2010, Nemesházi et al 2016. Still, some level of long distance gene flow was recently suggested in the Carpathian Basin population (Nemesházi et al 2016). NDD values published from different WTE populations differ considerably, with mean values ranging from about 30 to 114 km (Helander 2003, Struwe-Juhl & Grünkorn 2007, Whitfield et al 2009a.…”

“…Despite their juvenile vagrancy, similarly to other large raptor species, WTEs are philopatric (i.e. they start breeding relatively close to their natal area), as supported by both ringing data (Helander 2003, Helander & Stjernberg 2003, StruweJuhl & Grünkorn 2007, Whitfield et al 2009a and genetic structure of their wild populations (Hailer et al 2007, Honnen et al 2010, Nemesházi et al 2016. Still, some level of long distance gene flow was recently suggested in the Carpathian Basin population (Nemesházi et al 2016).…”

“…PCR profiles followed the original papers for Aa and Hal loci, and Hailer et al (2006) for IEAAAG loci, with some modifications (Nemesházi et al 2016 (Rousset 2008) was used to estimate pairwise linkage disequilibrium across loci. Consensus individual genotypes were prepared manually, based on genotypes of feathers collected at the same nest site (as described in Nemesházi et al 2018).…”

Results of Work of the Raptor Ringing Center of the Russian Raptor Research and Conservation Network in 2016

“…It can be expected a going from the wintering grounds to the breeding grounds and the formation of new pairs of birds from different nesting groups, as shown in particular by population-genetic studies of White-Tailed Eagle populations in Southern Europe (Nemesházi et al, 2016).…”

“…Можно предполагать миграцию с мест зимовки к местам гнездования и форми-рование новых пар птицами из разных гнездовых группировок, что показано, в частности, популяционно-генетическими исследованиями для популяций орланов Южной Европы (Nemesházi et al, 2016).…”