Among Accipitriformes sensu stricto, only a few species have been reported to form hybrid zones; these include the red kite Milvus milvus and black kite Milvus migrans migrans. M. milvus is endemic to the western Palearctic and has an estimated total population of 20–24,000 breeding pairs. The species was in decline until the 1970s due to persecution and has declined again since the 1990s due to ingestion of rodenticide-treated baits, illegal poisoning and changes in agricultural practices, particularly in its core range. Whereas F1 M. milvus × M. migr. migrans hybrid offspring have been found, F2 and F3 hybrids have only rarely been reported, with low nesting success rates of F1 hybrids and partial hybrid sterility likely playing a role. Here, we analyzed the mitochondrial (CO1 and CytB) and nuclear (Myc) DNA loci of 184 M. milvus, 124 M. migr. migrans and 3 F1 hybrid individuals collected across central Europe. In agreement with previous studies, we found low heterozygosity in M. milvus regardless of locus. We found that populations of both examined species were characterized by a high gene flow within populations, with all of the major haplotypes distributed across the entire examined area. Few haplotypes displayed statistically significant aggregation in one region over another. We did not find mitochondrial DNA of one species in individuals with the plumage of the other species, except in F1 hybrids, which agrees with Haldane´s Rule. It remains to be investigated by genomic methods whether occasional gene flow occurs through the paternal line, as the examined Myc gene displayed only marginal divergence between M. milvus and M. migr. migrans. The central European population of M. milvus is clearly subject to free intraspecific gene flow, which has direct implications when considering the origin of individuals in M. milvus re-introduction programs.

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In the years 1997 and 1998 we studied the home range and habitat use of the red kite with radio tracking in the region of Hakel 51.93 N; 11.16 E). We caught one male in both years. This male remained the whole time in the area where he hatched. We caught his female in 1998 and it remained close to the breeding place. During the nonbreeding season -the period between August and February -both partners used the same land section. The home range size (Minimum-Convex-Polygon, 95 %) we determined for the male at 8.0 (1997/98) and 6.2 km z (1998/99), the female used an area of 7,1 km 2. The monthly home ranges varied between 1.9 and 5.3 km 2 (male) and 1.4 and 4.4 km 2 (female). The chronological evolution of the area used by the two sexes was different. Whereas the female was flying over the biggest home range in August during the non-breeding time, this was the time of the smallest home range with the male. With the advancing season (sinking temperatures, first snows) and the reducing availability of prey, the home range were enlarged successively. One important food source was at a compost plant. Lanes and the male's place of hatching represented the main whereabouts. The surrounding areas of arable land were used little. During both non-breeding times we determined the roost place use of the male over a period in each case of 160 nights. While the male spent 18.1% of all nights away from the place of hatching in 1998/99, it did so only twice (1.3 %) the previous winter. We attribute this to lower temperatures in 1998/99 and see a rudimentary zugunruhe. The female slept away from this area only in eleven nights (6.9 %), Two other red kites showed a marked alternation of the roosting place. One female changed her roosting place eight times in 12 nights. Keywords:Red kite, home range, habitat use, overwintering, roosting place use. ZusammenfassungIn den Jahren 1997 und 1998 untersuchten wir mit Hilfe der Telemetrie Aktionsraum und Habitatnutzung von Rotmilanen im Bereich des Hakels 51,93 N; 11,16 E