In a study of the extent and timing of Red Kite
Milvus milvus
dispersal movements from Central Europe (Austria, the Czech Republic and Slovakia) using GPS telemetry, we found support for the ...hypothesis that Red Kite dispersal, including migration behaviour, is dependent on both age and sex. Examination of the tendency to stay in, or return to, a particular area in Red Kites indicated that, while part of the population remained in the natal area, most migrated to overwintering sites across a broad belt of southern European sites stretching from the Iberian Peninsula to the Balkans. Red Kites first bred at 2 years old, i.e. in their 3rd calendar year. Migration routes were significantly longer in females than males, while natal philopatry was significantly higher in males than females. The lengths of single-year migration routes decreased significantly over consecutive years, and breeding philopatry increased significantly in cases where previous breeding was successful.
•Habitat-associated breeding performance of Clanga pomarina on five scales studied.•Home-range and landscape scale predictors were the most important.•Logging operations pose agrave threat to ...species’ reproduction.•Species shows strong preference or even specialization for major forest ecotones.•Close-to-nature forestry is unlikely to comply with the species’ conservation goals.
Habitat loss and fragmentation along with altered disturbance regimes cause raptor population declines, but processes, rates and interactions are seldom known. Knowledge gaps remain mainly in large forest-dwelling raptors that use habitats on several spatial scales. Our study focusses on breeding habitats and habitat-associated breeding performance of the Lesser Spotted Eagle (“eagle”) across five spatial scales in Laborecká vrchovina Mts (East Carpathians, Slovakia) during 2011–2016. We calculated two relative measures of breeding performance (breeding attempt index, BAI; nest productivity index, NPI) and related them to habitat characteristics sampled on the nest-platform, nest-tree, nest-site, home-range and landscape scale. We found that eagle‘s breeding performance was best explained by predictors on the home-range and landscape scale. BAI and NPI strongly and consistently increased with increasing distance of nest to the nearest felling site and with occurrence of the nest site on lower slope landforms. Former finding supported ample evidence that logging operations pose agrave threat to eagle’s reproduction, while the latter hinted at its strong preference or even specialization for forest edges, for notably old regional ecotones between montane forests and submontane non-forest formations show lower slope topography. On the nest-site scale, nest productivity (NPI) significantly and strongly increased with increasing percentage of Sessile Oak (Quercus petraea) and decreased with cosine of slope aspect in response to more open and accessible canopy structure resulting from oak appearance in beech-dominated forests and to contrasts in solar radiation, shade and similar north–south effects. On the nest-platform and nest-tree scale breeding performance marginally significantly increased with increasing relative nest height above ground and decreased in nests of natural origin (in BAI). It pointed to unrecognized relevance of relative nest height that may link nest-tree with nest-site scale and reflect atrade-off between nest accessibility and nest protective cover, and to greater nest placement diversity with possible greater vulnerability of natural nests. Differences in breeding performance measured by BAI vs NPI indicated that certain selection pressures may vary significantly during the breeding cycle, e.g., early vs late breeding failures and subsequent learning from negative experience. We recommended several management actions by our results, particularly to advance systematic eagle monitoring, to address multiple scales of its habitat use according to their relative importance, to increase the width of protection zones around nests and adopt new or strengthen existing landscape-scale measures and to follow sustainable forestry as apart of integrated landscape management instead of close-to-nature forestry.
Abstract Table 1 in original paper (Slobodník et al. 2017, Slovak Raptor Journal 11: 83–89) was published with incorrect data. Correct version is published here.
The Red Kite Milvus milvus is endemic to the western Palearctic. While the largest breeding population is in Germany, the population density decreases substantially from central to eastern Europe. In ...2015, we tagged two young Red Kite females with telemetry loggers in an area with very low kite density in the northeastern part of Slovakia. One of these females failed to breed over her seven-year lifespan. After leaving her post-fledging area she never returned. During her first two years, she undertook two exploratory flights to Croatia and Romania, but remained exclusively in southwestern Slovakia and northeastern Hungary over the rest of her life. Throughout this period, she always wintered alone and no other Red Kites were ever observed in her wintering grounds. During the pre-breeding period (March-April), she remained outside the area that held breeding kite pairs, and there were no signs of breeding based on her positions during the breeding season. This seven-year-old is the oldest Red Kite floater recorded to date. Owing to the low density of Red Kite breeding pairs in Slovakia and Hungary, it is likely that she was unable to find a suitable mate prior to the beginning of the breeding season. In such areas, the role of floaters may prove critical for the persistence of low-density Red Kite populations.
In the years 2009-2012 a total of 316 individuals were marked in a colour ringing programme of the population ofA. pomarina in Slovakia. From this a total of 39 inds. were ringed with yellow readable ...plastic rings with a two-place alphanumeric code (all young in a nest) and 277 inds. (273 young and 4 adult inds.) with light-blue rings. For the entire period of the programme of marking the A. pomarina population in Slovakia in the years 2000-2012 a total of 952 inds. were ringed, 933 of which were young birds in nest and 19 adult individuals. In the period 2009-2012 48 records were obtained from observations of 35 individuals of different age categories (31 individuals from one to 11 years old, three of unknown age and one young individual about one month after fledging the nest). The age categories of immature individuals were determined, and six were found to be one-year-old individuals (12.5%) in the second calendar year of life after their first return from wintering grounds, six were two-year-old eagles (12.5%) and five were three-year-old eagles (10.4%) which spent breeding periods in Europe at a relatively small distance from their place of hatching. Adult individuals were found to be in their current breeding grounds at distances of 8-249 km from their hatching place. In the period 2000-2012 three individuals were recorded 3× and four individuals 2×. The results confirm breeding site fidelity in adults, but also the fidelity of immature individuals to their hatching place, and the return of one-year-old individuals from their wintering grounds to the vicinity of their hatching place immediately in the first year of life (that is, in the second calendar year).
V rokoch 2009-2012 sa na Slovensku oznacilo v programe farebného znacenia populácie A. pomarina 316 jedincov. Z toho žltými odcítatelnými plastovými krúžkami s dvojmiestnym alfanumerickým kódom spolu 39 jedincov (všetko mládatá na hniezde) a svetlomodrými krúžkami 277 jedincov (273 mládat a 4 adultné jedince). Za celé obdobie programu oznacovania populácie A. pomarina na Slovensku v rokoch 2000-2012 bolo oznacených 952 jedincov, z toho 933 mládat na hniezde a 19 dospelých jedincov. V období 2009-201 2 sa zistilo 48 záznamov o pozorovaní 35 jedincov rôznych vekových kategórií (31 jedincov jeden až jedenástrocných, tri jedince neznámeho veku a jeden mladý jedinec cca jeden mesiac po vyletení z hniezda). Determinované boli vekové kategórie immaturných jedincov, z ktorých bolo 6 jednorocných jedincov (12,5 %) v druhom kalendárnom roku života, po prvom návrate zo zimoviska, šest dvojrocných orlov (12,5 %) a pät trojrocných orlov (10,4 %), ktoré sa zdržiavali v hniezdnom období v Európe v relatívne malej vzdialenosti od miesta vyliahnutia. Adultné jedince boli zastihnuté vo vzdialenosti 8-249 km od miesta svojho vyliahnutia na svojich terajších hniezdiskách. V období rokov 2000-2012 tri jedince boli zaznamenané už 3×, štyri jedince 2×. Výsledky potvrdzujú vernost k hniezdisku u dospelých, ale aj vernost immaturných jedincov k miestam ich vyliahnutia a návrat jednorocných jedincov zo zimoviska do blízkosti miest ich vyliahnutia hned v prvom roku svojho života (teda v druhom kalendárnom roku).
The population of the red-footed falcon in Slovakia inhabits the north-western edge of the species' breeding range. This breeding population is relatively small and came near to extinction during the ...population decline of this species in central Europe in recent decades. Thanks to increasing numbers of breeding pairs in Hungary, the Slovak population began to grow again. Moreover, some differences in breeding biology associated with breeding in nest boxes were found. Here we describe the dependence of the small isolated breeding population in Slovakia on the core population in the more eastern parts of the Carpathian Basin, and the impact of supporting activities (nest boxes) on this raptor species in Slovakia.
In the period 1964-2007, data on 1472 ex. of prey was acquired from whole Slovakia. It was confirmed that the location of the breeding population on the foothills and mountains of the Carpathian Arc ...has a cardinal contribution to diet diversity. The breeding sites and hunting-grounds were found from 100 to 1 000 meters above sea level. The dominant part of the diet created mammalian species (88.11 %, 19 species and Sorex sp., Apodemus sp., undetermined Artiodactyla). Birds were less represented but with higher diversity of species (6.25 %, 24 species and Columba sp., undetermined Passeriformes). In comparison with birds, the share of Amphibia, Reptilia and Pisces together (4.89 %, 5 species and Rana sp., Lacerta sp., undetermined Serpentes and Reptilia) was lower. Pisces constituted only 0.007 % with 1 ex. of prey species Cyprinus carpio. Evertebrata constituted 0.75 % and species from orders Orthoptera, Coleoptera, and Diptera were found. The dominant prey of A. pomarina in Slovakia was Microtus arvalis (69.57 %), followed by Arvicola terrestris (5.16 %) and Microtus agrestis (3.94 %) constituting significantly lower proportion. These three species from the category small rodents composed 75.67 % of diet. Less abundant species in range 2.24-1.00 % were Talpa europaea (2.31 %), Rana temporaria (2.24 %), Cricetus cricetus (1.70 %), Phasianus colchicus (1.15 %), and Lepus europaeus (1.09 %). In lesser extent (1.0-0.5 %) also other mammalian species such as Apodemus flavicollis (0.88 %) and Mustela nivalis (0.88 %) were represented. The most frequently encountered birds were Galliformes such as P. colchicus (1.15 %), Gallus gallus domesticus (0.48 %), and Coturnix coturnix (0.54 %). Other more abundant prey bird species were Alauda arvensis (0.48 %), Columba sp. (0.48 %), and Crex crex (0.34 %). From the class Reptilia relatively high share of Anguis fragilis (0.95 %) and Lacerta sp. (0.68 %; most probably Lacerta agilis) were recorded. Other species with representation lower than 0.3 % were a random prey of A. pomarina.
V rokoch 1964-2007 sa získali údaje o 1472 kusoch koristi z celého Slovenska. Potvrdilo sa, že zásadný podiel na diverzite potravy má situovanie hniezdnej populácie do predhorí a pohorí Karpatského oblúka. Hniezdiská a loviská sa zistili v nadmorských výškach od 100-1000 m. Dominantnú zložku tvorili cicavce (88,11 %, 19 druhov a Sorex sp., Apodemus sp., neurčené Artiodactyla). Vtáky sú zastúpené oveľa menej početne, no s väčšou druhovou diverzitou (6,25 %, 24 druhov a Columba sp., neurčené Passeriformes). V menšej miere v porovnaní s vtákmi je zastúpenie spoločnej skupiny Amphibia, Reptilia a Pisces (4,89 %, 5 druhov a Rana sp., Lacerta sp., neurčené Serpentes a Reptilia). Z toho Pisces tvorili len 0,007 % s jediným kusom koristi druhu Cyprinus carpio. Evertebrata tvorili 0,75 %, tvorených zástupcami radov Orthoptera, Coleoptera a Diptera. Dominantnou korisťou A. pomarina na Slovensku je hraboš poľný (Microtus arvalis, 69,57 %), po ňom nasleduje so značným odstupom hryzec vodný (Arvicola terrestris, 5,16 %) a hraboš močiarny (Microtus agrestis, 3,94 %). Tieto tri druhy z kategórie drobných hlodavcov tvorili 75,67 % potravy. Menej početnými druhmi zistenými v potrave v rozsahu 2,24-1,00 % boli krt obyčajný (Talpa europaea, 2,31 %), skokan hnedý (Rana temporaria, 2,24 %), chrček poľný (Cricetus cricetus, 1,70 %), bažant poľovný (Phasianus colchicus, 1,15 %) a zajac poľný (Lepus europaeus, 1,09 %). Z ostatných cicavcov sa v menšej miere (1,0-0,5 %) vyskytovali ryšavka žltohrdlá (Apodemus flavicollis, 0,88 %) a lasica myšožravá (Mustela nivalis, 0,88 %). Z vtákov boli najčastejšie zastúpené kurotvaré (Galliformes), a to bažant poľovný (P. colchicus, 1,15 %), kura domáca (Gallus gallus dom., 0,48 %) a prepelica poľná (Coturnix coturnix, 0,54 %). Ďalšie početnejšie lovené druhy vtákov boli škovránok poľný (Alauda arvensis, 0,48 %), holuby (Columba sp., 0,48 %) a chriašteľ poľný (Crex crex, 0,34 %). Z triedy Reptilia sa zistilo pomerne vysoké zastúpenie u slepúcha lámavého (Anguis fragilis, 0,95 %) a jašterice (Lacerta sp., 0,68 %; s najväčšou pravdepodobnosťou jašterica krátkohlavá, Lacerta agilis). Ostatné druhy s dominanciou pod 0,3 % sú náhodnou korisťou A. pomarina.
Several estimates of the lesser spotted eagle breeding population in Slovakia were published in 1955-2002. In this study we estimate the breeding population of the lesser spotted eagle by 1997 and ...2014. By 1997, the estimated size of the breeding population was 762 pairs. In 2002 an estimate of the population size by 2000 was published at 800-900 pairs. By 2014 we estimate the breeding population of the lesser spotted eagle in Slovakia at 600-800 pairs and the declining population trend in 2000-2013 at -23%. Our estimate is supported by the extrapolation from data obtained in 2011-2013 in eight selected Special Protection Areas (SPAs) within a framework of the project LIFE09 NAT/SK/000396 “Conservation of Aquila pomarina in Slovakia”. When analyzing abundance, density and trends in the species’ entire breeding range in Slovakia we first summarised the numbers of breeding pairs, their densities and trends within the selected SPAs and then explored the differences among them using ANOVA and cluster analysis. For the eight SPAs as a whole (n = 8) or partitioned by a grid of the Databank of Slovak Fauna (n = 119 squares) we calculated the interval estimates of the mean number of pairs (unweighted and weighted arithmetic means and medians). By summarising these estimates and extrapolating to the species’ entire breeding range in Slovakia (c. 28,935 km2) while increasing the sample size (n = 8, 9, 11 and 1 2 SPAs), the size estimates stabilise at a level of 670 (mean with 95%LCL = 507 and 95%UCL = 834) or 765 (median with 95%LCL = 393 and 95%UCL = 841 ) breeding pairs. The most reliable estimate of the breeding population of the lesser spotted eagle in Slovakia by 2014 is a median of 765 pairs with a 95% confidence interval from 393 to 841 pairs and an interquartile range from 418 to 835 pairs. We estimate a 23% decrease in the breeding population during 2000-2013, i.e. a small decrease -1 (20-49%). Three methods of estimating were used: 1 ) comparing the numbers of pairs in the selected SPAs between 2000 and 2014 - indicates a decrease of -26%; 2) comparing the numbers of pairs from long-term monitoring in five areas (orographic units Vihorlatské vrchy Mts, Laborecká vrchovina Upland, Volovské vrchy Mts, Orava and Horné Ponitrie Regions) by the 1990s and 2014 - indicates a decrease of -20%; 3) comparing the numbers of pairs by 1997 in selected areas within the boundaries of the current SPAs with the number of pairs in the same SPAs by 2014 - indicates a decrease of -23%. In the eight selected SPAs the estimated decline was even more pronounced, reaching a median trend of -35% in the 95% confidence interval from -54% to +25%. The estimate by 1997 fits in with an increasing trend of published breeding population estimates in Slovakia during 1955-2002. The estimate by 2014 is lower than the estimate by 2000, and for the first time ever a declining trend is recorded. By 2014 the breeding grounds of the lesser spotted eagle in Slovakia embrace an area of c. 28,935 km
. Taking an estimate of 600-800 breeding pairs, the mean density varies between 2.1-2.8 pairs.100 km
Odhad pocetnosti hniezdnej populácie orla kriklavého na Slovensku bol publikovaný v rokoch 1955-2002. V tejto štúdii odhadujeme pocetnost hniezdnej populácie orla kriklavého k rokom 1997 a 2014. K roku 1997 bol odhadnutý celkový pocet 762 párov. V roku 2002 bol publikovaný odhad pocetnosti k roku 2000 vo výške 800-900 párov. K roku 2014 odhadujeme pocetnost hniezdnej populácie orla kriklavého na Slovensku na 600-800 párov a klesajúci trend vývoja populácie v rokoch 2000-2013 priemerne -23%. Náš odhad je podložený výsledkami extrapolácie údajov, získaných v rokoch 2011-2013 z ôsmich vybraných chránených vtácích území v rámci riešenia projektu LIFE09 NAT/SK/000396 „Ochrana orla kriklavého na Slovensku“. Pri štatistickej analýze pocetnosti, hustôt a trendov pre celý areál hniezdneho rozšírenia druhu na Slovensku sme vychádzali zo sumarizovaných poctov hniezdnych párov, ich hustôt a trendov vo vybraných územiach a z ich stratifikácie podla výsledkov ANOVA a zhlukovej analýzy. Pre 8 chránených vtácích území vcelku (n = 8) i v clenení podla kvadrátov Databanky Fauny Slovenska (n = 119) sme vypocítali intervalové odhady stredných hodnôt poctu párov (prosté i vážené aritmetické priemery a mediány). Ich sumarizáciou pri postupnom zväcšovaní vzorky (n = 8, 9, 11a 12) a extrapoláciou na celý areál hniezdneho rozšírenia druhu na Slovensku (ca 28 935 km2) sa výsledné odhady stredných hodnôt stabilizovali na úrovni 670 (aritmetický priemer s 95%LCL = 507 a 95%UCL = 834) resp. 765 (medián s 95%LCL = 393 a 95%UCL = 841) hniezdnych párov. Ako najspolahlivejší odhad pocetnosti hniezdnej populácie orla kriklavého na Slovensku k roku 2014 vychádza medián 765 párov v 95 %-nom intervale spolahlivosti od 393 do 841 párov a s medzikvartilovým rozpätím od 418 do 835 párov. Odhadujeme 23 %-ný pokles celoslovenskej populácie v rokoch 2000-2013, co predstavuje mierny pokles -1 (20-49 %). Vychádza z troch spôsobov odhadovania: 1) porovnanie poctu hniezdnych párov vo vybraných chránených vtácích územiach k roku 2000 a 2014 - poukazuje na pokles -26 %; 2) porovnanie poctu hniezdnych párov v piatich dlhodobo monitorovaných územiach orografických celkov Vihorlatské vrchy, Laborecká vrchovina, Volovské vrchy a regiónov Orava a Horné Ponitrie v 90- tych rokoch 20. storocia a k roku 2014 - poukazuje na pokles -20 %; 3) porovnanie poctu hniezdnych párov k roku 1997 vo vybraných územiach v hraniciach súcasných chránených vtácích území s poctom hniezdnych párov v tých istých chránených vtácích územiach k roku 2014 - poukazuje na pokles -23 %. V 8 vybraných chránených vtácích územiach bol štatisticky odhadnutý pokles pocetnosti hniezdnej populácie A. pomarina ešte výraznejší, a to až na úrovni mediánového trendu -35 % v 95 %-nom intervale spolahlivosti od -54 % do +25 %. Odhad k roku 1997 zapadá do vzostupného trendu vývoja publikovaných odhadov pocetnosti hniezdnej populácie druhu na Slovensku v rokoch 1955-2002. Odhad k roku 2014 ukazuje už menší pocet hniezdnych párov v porovnaní s odhadom k roku 2000 a prvýkrát v histórii sa zaznamenáva klesajúci trend. K roku 2014 sa hniezdny areál orla kriklavého na Slovensku rozprestiera na ploche ca 28935 km
a pri odhadovanom pocte 600-800 hniezdnych párov je denzita priemerne 2,1-2,8 hniezdnych párov.100 km
.
In 2011–201 4 monitoring of the lesser spotted eagle (Aquila pomarina) breeding population was conducted in eight
special protection areas in Slovakia. From a total of 272 successful breeding ...attempts by 1 49 breeding pairs during 4 breeding
seasons 277 young birds were fledged. The average reproductive success ratio was thus 0.51 juv./pair present, 0.69 juv./breeding
pair and 1 .37 juv./1 00 km2. In the surveyed period a total of 1 51 protection zones were established around the nests in 11 9 breeding
territories, which provided protection for 1 7% of the breeding population of the lesser spotted eagle in Slovakia. By testing
the effectiveness of protection zones it was determined that in nests with an established protection zone the probability of successful
raising of young is higher in comparison with nests without such a zone. The probability that breeding will be successful in the
nests of breeding pairs without a protection zone was 48.1% (95% confidence intervals (CIs): 37.4–59.0%), and in nests with
a protection zone 64.8% (95% CIs: 59.8–69.6%). Among the five most frequent nest tree species used by A. pomarina in Slovakia
for breeding are Picea abies 61 × (28.4%), Pinus sylvestris 45× (20.9%), Quercus sp. 36× (1 6.7%), Fagus sylvatica 25× (11 .6%)
and Abies alba 1 8× (8.4%). Among the rarer nest tree species used are Larix decidua 1 2× (5.6%) and Alnus glutinosa 3× (1 .4%),
while a further 11 species of nest trees did not achieve even 1%. The highest number of nest trees (n = 21 5), i.e. 34 nests (1 5.8%),
was found in the altitude range of 401–450 m a.s.l. and 29 nests (1 3.5%) at 351–400 m a.s.l. Other altitude zones were all below
the 1 0% mark. A total of 54% of nests found (11 6 nests) are located in the altitude zone of 301–600 m a.s.l., and 71 nests (33%)
in the zone 600–900 m a.s.l. The lowest situated nest was at an altitude of 1 50 m and the highest at 950 m; the average was
595.01 m a.s.l. The highest number of nests (n = 209) were located on trees in a range 1 5.1–20.0 m above the ground (n = 92,
44%), while the lowest nest found was at a height of 5 m and the highest at 30 m above the ground.
V rokoch 2011 – 2014 sa realizoval monitoring hniezdnej populácie orla krikľavého (Aquila pomarina) v ôsmich chránených vtáčích územiach na Slovensku. U 149 hniezdnych párov z celkových 272 úspešných hniezdení počas 4 hniezdnych sezón vyletelo 277 mláďat. Priemerná reprodukčná úspešnosť predstavovala 0,51 juv./prítomný pár, 0,69 juv./hniezdiaci pár a 1,37 juv./100 km2. V uvedenom období bolo okolo hniezd orlov krikľavých ustanovených celkom 151 ochranných zón, ktoré zabezpečili ochranu 119 hniezdnych teritórií, čo predstavuje cca 17 % hniezdnej populácie orla krikľavého na Slovensku. Testovaním účinnosti ochranných zón sa zistilo, že v hniezdach s vyhlásenou ochrannou zónou je vyššia pravdepodobnosť úspešného odchovania mláďat v porovnaní s hniezdami bez takejto zóny. Pravdepodobnosť, že hniezdenie bude úspešné v hniezdach hniezdiacich párov bez ochrannej zóny bola 48.1% (95% confidence intervals (CIs): 37.4–59.0%), v hniezdach s ochrannou zónou 64.8% (95% CIs: 59.8–69.6%). Medzi 5 najčastejšie využívaných hniezdnych stromov na hniezdenie A. pomarina na Slovensku patrí Picea abies 61× (28,4%), Pinus sylvestris 45× (20,9%), Quercus sp. 36× (16,7%), Fagus sylvatica 25× (11,6%) a Abies alba 18× (8,4%). Medzi zriedkavejšie druhy hniezdnych stromov patrí Larix decidua 12× (5,6%) a Alnus glutinosa 3× (1,4%), ďalších 11 druhov hniezdnych stromov nedosiahli 1 %. Najvyšší počet hniezdnych stromov (n = 215), tj. 34 hniezd (15,8%) sa nachádzal v intervale nadmorskej výšky 401 – 450 m a 29 hniezd (13,5%) v intervale 351 – 400 m n. m. Ostatné výškové pásma boli pod hranicou 10%. 54% zistených hniezd (116 hniezd) sa nachádza vo výškovom pásme 301 – 600 m n. m., 71 hniezd (33%) v pásme 600 – 900 m n. m. Najnižšie situované hniezdo bolo v nadmorskej výške 150 m a najvyššie 950 m, priemer bol 595,01 m. Najvyšší počet hniezd (n = 209) bol na strome umiestnený v rozmedzí 15,1 – 20,0 m (n = 92, 44,02%). Najnižšie zistené hniezdo bolo vo výške 5 m a najvyššie 30 m nad zemou.
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.
V rokoch 2000-2008 sa na Slovensku označilo farebnými odčítateľnými krúžkami s dvojmiestným kódom spolu 636 jedincov orlov krikľavých (Aquila pomarina), čo je najviac takto označených orlov krikľavých v Európe. Z tohto počtu bolo 621 ex. (97,6 %) mláďat na hniezde a 15 ex. (2,4 %) adultných vtákov, ktoré sa odchytili a následne okrúžkovali. V uvedenom období sa použili na Slovensku dve série farebných krúžkov. Žltými krúžkami sa začalo krúžkovať v roku 2000, do konca roku 2008 sa nimi označilo 631 jedincov (616 mláďat a 15 adultných jedincov). Svetlomodrou sériou krúžkov sa začalo krúžkovať v roku 2008 a označilo sa nimi 5 mláďat na hniezde. Súbežne s odčítateľnými krúžkami sa používali aj klasické ornitologické krúžky krúžkovacích staníc v Čechách (NM Praha) a na Slovensku (NM Bratislava). Žltá séria sa v menšej miere použila aj v Nemecku a Poľsku na označenie orla krikľavého (Aquila pomarina), orla hrubozobého (Aquila clanga), prípadne ich hybridov. V predloženom článku autori uvádzajú prvé pozorovania takto označených orlov krikľavých vo voľnej prírode na Slovensku. Pozorované orly boli vo veku 1, 2, 4, 5, 7 a 8 rokov od ich vyliahnutia. V niektorých prípadoch to už boli hniezdiace jedince zastihnuté pri odchovávaní svojich mláďat.
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