Monitoring of spotted eagles in Estonia in 1994–2014: Stability of the lesser spotted eagle (Aquila pomarina) and decline of the greater spotted eagle (A. clanga)

Population trends of the lesser and greater spotted eagle in Estonia were comparatively estimated using data obtained in 1994-2014 from the monitoring scheme of common raptors and from special plots for monitoring of spotted eagles. Both approaches had pros and cons, but resulted in similar population trends. The numbers of the lesser spotted eagle have had minor fluctuations over the last two decades but the overall trend is stable; the current population size is estimated as 600-700 pairs. The number of greater spotted eagle breeding territories (pure-species and mixed pairs pooled) have significantly decreased, for example by 14% per year in 2004-2010, though in recent years the numbers seem to be stabilised at a critically low level. The decline of pure-species pairs was somewhat steeper than that ofmixed pairs, their proportion decreasing from a third to a quarter of the greater spotted eagle breeding territories. Altogether 5-10 breeding territories of the greater spotted eagle may be found nowadays in Estonia.

Reproductive success, selected nest characteristics and the effectiveness of establishing protection zones of the lesser spotted eagle (Aquila pomarina) population in Slovakia

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.

Abstracts of contributions presented at the International Conference on the Conservation of the Lesser Spotted Eagle, Slovakia, 2014

The International Conference on the Conservation of the Lesser Spotted Eagle (Aquila pomarina) was held on September 25-27, 2014 in Lesanka Guesthouse at Košická Belá, Slovakia. The Conference was organized within the framework of the project LIFE09NAT/SK/000396 Conservation of Aquila pomarina in Slovakia, implemented by Raptor Protection of Slovakia, Východoslovenská energetika, a.s., Stredoslovenská energetika, a.s., and Stredoslovenská energetika - Distribúcia, a.s. This project was cofinanced by EU-LIFE and the Ministry for the Environment of the Slovak Republic. A total of 59 participants from 14 countries attended the conference. The conference agenda included 17 presentations and 7 posters. Some of the contributions are published in Slovak Raptor Journal volume 9 (2015) as full papers, and a further 23 contributions are published here as conference abstracts.

International Conference on the Conservation of the Lesser Spotted Eagle, Košická Belá, Slovakia, 2014

The International Conference on the Conservation of the Lesser Spotted Eagle (Aquila pomarina) was held on September 25-27, 2014 in Lesanka Gesthouse at Košická Belá, Slovakia. It was organised by Raptor Protection of Slovakia (RPS) in cooperation with Východoslovenská energetika Holding a.s. The conference dealt with (i) delivering further inputs for updating the European Action Plan for the species, (ii) sharing information on biology and ecology of the species, and (iii) exchange of experience with best practice and innovative species conservation measures. A total of 59 participants from 1 4 countries attended the conference. The agenda included 17 presentations and 7 posters. Some of the contributions are published in Slovak Raptor Journal volume 9 (2015) as full papers, and a further 23 contributions are published as abstracts. The conference also included two field trips during which participants had the opportunity to observe the installation of console barriers on poles of 22 kV power lines, and typical habitats of the lesser spotted eagle. The conference was organized within the framework of the project LIFE09NAT/SK/000396 Conservation of Aquila pomarina in Slovakia, implemented by Raptor Protection of Slovakia, Východoslovenská energetika Holding a.s., Stredoslovenská energetika, a.s. and Stredoslovenská energetika-Distribúcia, a.s. The project was cofinanced by EU-LIFE and the Ministry for Environment of the Slovak Republic.

Abundance, distribution and trend of the lesser spotted eagle (Aquila pomarina) breeding population in Slovakia

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 km2. Taking an estimate of 600-800 breeding pairs, the mean density varies between 2.1-2.8 pairs.100 km-2.

Current situation and population trend of the lesser spotted eagle (Aquila pomarina) in Hungary

First reports on the population of the lesser spotted eagle in Hungary appeared between 1978 and 1982, and based on these data, we estimate that their population was about 90 pairs during that period. By 2014 this number had decreased to below 40 pairs. The species disappeared from its former nesting sites in the lowlands, riparian habitats and also in a few hilly and mountainous areas. The reasons for its decline appear complex in Hungary. Changes in agricultural practice are suspected of being one of the main reasons which are discussed in the article. We presume that populations of prey species were also negatively affected. Decrease in undisturbed forest stands older than 100 years was probably also a significant factor affecting nesting habitats. As a marginal population, it greatly depends on the larger ones in the surrounding countries, and it is also affected by mortality during migration. Positive changes in the past four years in agricultural land use have already caused a slight increase in their numbers. Main tasks for the near future should be the establishment of a special support scheme focusing on the species’ foraging habitats.

Colour ringing programme of the lesser spotted eagle (Aquila pomarina) population in Slovakia and its new results in the period 2009–2012

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).