Abstract
In Slovakia during 2000-2008, 636 Lesser Spotted Eagles (Aquila pomarina) were marked with readable colour rings with double figure code. This is the highest number of Lesser Spotted Eagles marked in such a way in Europe. From this sample, 621 ind. (97.6 %) were chicks at the nest and 15 ind. (2.4 %) were adult birds which were trapped and consequently ringed. In this period, 2 colour series of rings have been used in Slovakia. In 2000 the ringing started with yellow rings, and up until the end of 2008, 631 ex. (616 young and 15 adults) were ringed. In 2008, the ringing started with light blue series of rings and 5 young at the nest were ringed. In addition to readable rings, aluminium ornithological rings of the Ringing Centres of Czech Republic (NM Praha) and Slovakia (NM Bratislava) have been used. The yellow series was used in fewer numbers also in Germany and Poland for marking the Lesser Spotted Eagle (Aquila pomarina), the Greater Spotted Eagle (Aquila clanga), and eventually their hybrids. In this article the authors reported first observations in Slovakia of such marked Lesser Spotted Eagles in the field. Observed eagles were 1, 2, 4, 5, 7 and 8 years old. Some of them were already breeding and were observed taking care of their chicks.