Prioritizing renewable energy generation over the conservation of natural habitats and species on a large spatial scale, leads to the paradox of impacting biodiversity to mitigate climate change. In this study, we aim at quantifying the long-term demographic impact of the excess mortality caused by collisions with wind turbines on the populations of two vulture species of conservation concern. Using long-term monitoring data and Integrated Population Models (IPMs), we quantified demographic parameters and projected population trends under various wind power development scenarios. Our findings indicate that even under our most optimistic scenarios, annual collision mortality could reach up to 30 % of the current Cinereous vulture population and 7 % of the Griffon vulture population. Without further wind power expansion, both vulture populations are predicted to remain stable or increase over the next 20 years. However, the addition of 85 wind turbines is likely to drive the Cinereous vulture to local extinction within 18 years and significantly slow the growth of the Griffon vulture population. Scenarios involving larger numbers of turbines could result in the extinction of both species within two to five years for Cinereous vultures and up to 20 years for Griffon vultures, depending on space use intensity. Our results underscore the vulnerability of long-lived species to excess mortality and highlight the need for comprehensive Environmental Impact Assessments (EIAs) that incorporate population dynamics analyses. Effective conservation strategies must include rigorous pre- and post-construction monitoring, the availability of monitoring data, and cumulative impact assessments that consider the entire foraging range of these species. Additionally, strategic planning to avoid critical vulture habitats and implementing mitigation measures in buffer zones are essential. This study emphasizes the necessity of integrating biodiversity considerations into renewable energy planning to balance the goals of energy production and wildlife conservation.

Natal dispersal is a crucial period for raptors with serious implications for individuals’ survival and population demography. In this study we analyzed data from 18 GPS-tracked golden eagles in order to describe their dispersal ecology in northern Greece, where the species feeds mostly on tortoises. Young eagles in our population dispersed at 176 days post fledging, spent their first year of independence relatively close (40–60 kms) to their natal ranges and exhibited a variable temporary settlement behavior. Overall dispersal range sizes did not differ seasonally, but temporary settlement area range sizes were significantly larger in winter. Three eagles survived to territorial settlement and occupied ranges 20–60 kms from their natal areas. The application and refinement of the Scottish GET dispersal ranging model suggested that eagles used areas that had higher topographical relief and lower canopy cover during their natal dispersal. Habitat heterogeneity seems to also be influential during temporary settlement. Our study is the first to provide both such insights for golden eagles in southern eastern Europe and a method for delineating temporary settlement areas for the species. Our findings can be explained in terms of food and habitat availability. We highlight the importance of conserving heterogeneous open areas of complex topography and applying proactive management measures within temporary settlement areas for our population’s conservation.

The main reasons for the global biodiversity decline are the destruction and degradation of natural habitats caused by human activity by transforming them into agricultural lands. Although this transformation has been linked with decreased biodiversity, some bird species might have learned how to benefit from newly created habitats. We studied home ranges and habitat preferences for daytime activity and roosting of two sedentary Marsh Harriers (Circus aeruginosus) from the Evros Delta and the Mediterranean coast of the Iberian Peninsula using the results of satellite telemetry tracking. The size of the home range for the bird tagged in the Evros Delta was 158 km2 (dynamic Brownian Bridge Movement Model, 95 %), while for the Iberian bird, this was more than nine times greater (1488 km2). Monthly home ranges noticeably increased during winter in Evros Delta in both years.. The birds chose habitats such as non-irrigated arable land, watercourses, inland marshes, and dump sites for daytime activity. In contrast, they avoided habitats like rice fields and complex cultivation patterns. Water-related natural habitats like inland and salt marshes were intensively used as nocturnal roosts. Despite the general negative effect of human pressure, our results showed that the species seemed to tolerate and benefit from some types of humanized environments of estuarine landscapes.

Golden Eagles are resident in Greece and known to feed mainly on tortoises when breeding. However, information on alternative prey is scarce, especially during the tortoise brumation, that roughly coincides with the eagles’ non-breeding season. We analyzed 827 prey items collected from 12 territories over five territory years and 84 records of eagles hunting or feeding behavior. Tortoises dominated the breeding season diet (71% of prey categories on average) and over half of all hunting/feeding observations. While no spatial structure was evident, habitat variables such as forest canopy cover were important associates in golden eagle diet seasonally. A significant seasonal pattern emerged in diet diversity, using a subset of six territories with at least 10 samples per season. Eagles shifted from a narrow, reptile- based breeding season diet dominated by tortoises to a broader non-breeding season diet, that included more carrion, mammals and birds. Breeding season specialization on ectothermic prey is a trait usually associated with migratory raptors in the Western Palearctic. The observed dietary diversity expansion accompanied by residency in the absence of ectothermic prey, highlights the adaptability of the golden eagle, a generalist predator. Tortoise populations in Greece are of conservation concern and land use changes as well as climate change, such as development and land abandonment may increase the prevalence of catastrophic megafires, exacerbating the threats to the golden eagle’s main prey when breeding. We discuss this and other diet related conservation implications for the species in northern Greece.

Lesser Spotted Eagle is a medium sized raptor with a stable population within its breeding range. Nonetheless, its favourable habitats (a mosaic of forest and low-vegetation forest-openings, often with water elements such as small ponds and flowing streams), are suffering from land abandonment as a result of abrupt socio-economic changes related to rural depopulation and the decline of traditional agro-silvo-pastoral practices. The species' breeding population in Dadia National Park (Dadia NP) of approximately 20 pairs, is an important stronghold at the southern fringe of its European breeding range. The breeding territories and their spatial distribution trends were studied in Dadia NP for 35 years (1979 to 2012). The overall interannual trend was not statistically significant for the population, with a minimum value of 17 pairs (2001 and 2012) to a maximum of 22 (2005). Despite this long-term stability though, territories' distribution in Dadia NP has changed remarkably. During the 1970s, a more uniform and clearly territorial distribution had been observed in the western part of Dadia NP, the stronghold of the species. It was an area characterized predominantly by forests, mixed with small-extension open landscapes, an optimal foraging and breeding landscape for the species. In contrast, in the 21st Century the population has shifted progressively to the eastern forest lowlands of Dadia NP adjacent to agricultural land, demonstrating a clustered distribution with reduced territory distances in an agro-forest area, not considered optimal for Lesser Spotted Eagle. This noticeable spatial change could be related to a decline in forest openings and habitat mosaics to the western part, as a result of land abandonment. Thus, the most suitable region for the species, decreased from 66% in 1979 to 54% in recent years, and specifically in Zone A of the National Park the most radical change was observed (from 80% to 53%). In conclusion, increased landscape homogeneity and reforestation of open areas could be major threats to the viability of Lesser Spotted Eagle. This has forced the species to shift its breeding territories already towards more humanized areas, in a more clustered distribution and expose them to human induced risks. Conservation policies should strive to increase heterogeneity at the landscape level and decrease the ecological impact of land abandonment.

Wind farm development can combat climate change but may also threaten bird populations' persistence through collision with wind turbine blades if such development is improperly planned strategically and cumulatively. Such improper planning may often occur. Numerous wind farms are planned in a region hosting the only cinereous vulture population in southeastern Europe. We combined range use modelling and a Collision Risk Model (CRM) to predict the cumulative collision mortality for cinereous vulture under all operating and proposed wind farms. Four different vulture avoidance rates were considered in the CRM. Cumulative collision mortality was expected to be eight to ten times greater in the future (proposed and operating wind farms) than currently (operating wind farms), equivalent to 44% of the current population (103 individuals) if all proposals are authorized (2744 MW). Even under the most optimistic scenario whereby authorized proposals will not collectively exceed the national target for wind harnessing in the study area (960 MW), cumulative collision mortality would still be high (17% of current population) and likely lead to population extinction. Under any wind farm proposal scenario, over 92% of expected deaths would occur in the core area of the population, further implying inadequate spatial planning and implementation of relevant European legislation with scant regard for governmental obligations to protect key species. On the basis of a sensitivity map we derive a spatially explicit solution that could meet the national target of wind harnessing with a minimum conservation cost of less than 1% population loss providing that the population mortality (5.2%) caused by the operating wind farms in the core area would be totally mitigated. Under other scenarios, the vulture population would probably be at serious risk of extinction. Our 'win-win' approach is appropriate to other potential conflicts where wind farms may cumulatively threaten wildlife populations.

Harnessing wind energy is seen as an environmentally friendly strategy to combat climate change. However, adverse environmental impacts have come to light for species that are prone to collision with wind turbine blades, such as vultures, leading to a conflict between wind energy industry and conservation. Our study area epitomized such a conflict, containing the only population of cinereous vultures in south-eastern Europe while also being the location for substantial existing and planned wind farms. We used long-term remote telemetry data to produce a species-specific sensitivity map for guiding wind energy development and to estimate vulture collision mortality due to currently operating wind farms. Most operational wind farms were in the population core area and in the highest priority areas for vulture conservation. Collision mortality due to the thirteen operating wind farms was estimated by combining global position system (GPS) telemetry data on vulture space use with a collision risk model (CRM). Estimated mortality varied greatly according to the CRM's ‘avoidance rate’. Under the most likely avoidance rates annual predicted collision mortality was 5–11% of the population, creating risk of population decline. Collision mortality was expected almost exclusively in the population core area, rendering further future development plans there severely problematic for vulture population persistence. Our sensitivity map, as a conservation prioritization system, offered a spatially explicit solution to the conflict between wind energy development and vulture conservation. Combining spatial use models derived from telemetry data with collision mortality models offers a novel conservation tool for evaluating large scale wind energy development proposals.

The aim of this study was to record the Schirmer tear test I (STT I) measurements in free-living vultures in order to estimate normal values. The Eurasian black vulture (Aegypius monachus), which breeds in the Mediterranean region and Asia, is listed as near threatened; it is also classified as vulnerable at the European level and endangered in Greece. The griffon vulture (Gyps fulvus), once widespread across the continent, has undergone a dramatic decline which has led to its extinction in many regions. Sixty-two animals were examined in total including 54 black vultures and 8 griffon vultures. The birds were classified into five age groups while four age groups were then combined into one large group: free-flying. STT I measurements and complete ophthalmic examinations were performed. Mean STT I value for black vultures was 10.9 +/- 3.3 mm/min (right eye, oculus dexter, OD) and 11.9 +/- 3.3 mm/min (left eye, oculus sinister, OS) and for griffon vultures was 6.4 +/- 1.8 mm/min OD and 6.5 +/- 1.8 mm/min OS. In both eyes, STT I values in black vultures were significantly higher than those recorded in griffon vultures. Intraspecific comparisons yielded a significant difference between eyes of black vultures but not between those of griffon vultures, with OS producing higher STT I readings than did OD. When STT I was compared between OD and OS for each age group separately, a statistically significant difference was detected in the immature and free-flying black vultures. In addition, black vulture hatchlings had a significantly higher tear production than did free-flying juveniles, immatures, subadults, and adults. STT I values in black vultures are similar to those reported in other Accipitriformes but are lower in griffon vultures. This difference is probably related to anatomic, evolutionary, and feeding factors and requires further investigation.

Several recent impact studies reveal that in some localities industrial wind farms are associated with high numbers of bat fatalities. In Europe, most published studies have been conducted in the northwest, while bat diversity generally is much higher in the south of the continent. Here we provide evidence from a post-construction monitoring study conducted in north-eastern Greece between August 2009 and July 2010. Overall, 88 turbines from nine wind farms were intensively searched, and 181 dead and two injured bats were found in their proximity. The most frequently killed species were Nyctalus leisleri (n = 56), Pipistrellus pipistrellus/P. pygmaeus (53), P nathusii (35), Hypsugo savii (23) and N. noctula (10). Fatality rates were high from June to September. Most killed bats were adult males. Observed differences in the temporal pattern of fatalities among species may be associated with differences in their behaviour and distribution. Sex segregation with males at higher elevation, where the wind farms were located, and/or absence of females from such areas during summer may be the reason behind the higher male mortality rates. Bat fatalities were unequally distributed among wind farms and turbines. Four turbines (5%) accounted for 27% and 13 turbines (15%) for 51% of the fatalities. The most frequently killed species exhibited different spatial patterns of fatality, presumably because some turbines were located closer to roosts and/or commuting corridors. Fatalities were positively correlated with tower height but not with rotor size. To reduce bat fatalities, we recommend an increase in the cut-in speed of turbines responsible for fatalities from sunset to sunrise.

The article presents the results of the first tagging of a young Eastern Imperial Eagle (Aquila heliaca SAVIGNY 1809) with a GPS / GSM transmitter in Bulgaria. The device was a prototype of the Spanish company EagleEye(R). The transmitter was fitted on a young Imperial Eagle successfully treated in the Wildlife Rescue Centre of Green Balkans. The bird was released back into the wild at 150 days of age in the end of November 2007. The eagle started migrating to the South after the release. During this intensive movement, the tagged Imperial Eagle flew over two continents - Europe and Asia and crossed the borders of three countries - Bulgaria, Turkey and Greece. The behavior of this bird was completely different from that of the other two Imperial Eagles of the same age, studied at the same time through radio-tracking. They stayed to winter in Bulgaria, while the GPS / GSM tagged bird was obviously heading for Africa, flying over wide marine areas. An area on the north coast of the Marmara Sea, where the bird remained for a while, was located during the study. A total of 869 positions with the exact location of the bird were received during the study period. Data on the duration of the daily passage and the height of the flight was also gathered.

The article presents the results of the first tagging of a young Eastern Imperial Eagle (А quila heliaca s av i g N y 1809) with a GPS / GSM transmitter in Bulgaria. The device was a prototype of the Spanish company EagleEye®. The transmitter was fitted on a young Imperial Eagle successfully treated in the Wildlife Rescue Centre of Green Balkans. The bird was released back into the wild at 150 days of age in the end of November 2007. The eagle started migrating to the South after the release. During this intensive movement, the tagged Imperial Eagle flew over two continents – Europe and Asia and crossed the borders of three countries – Bulgaria, Turkey and Greece. The behavior of this bird was completely different from that of the other two Imperial Eagles of the same age, studied at the same time through radio-tracking. They stayed to winter in Bulgaria, while the GPS / GSM tagged bird was obviously heading for Africa, flying over wide marine areas. An area on the north coast of the Marmara Sea, where the bird remained for a while, was located during the study. A total of 869 positions with the exact location of the bird were received during the study period. Data on the duration of the daily passage and the height of the flight was also gathered.

In the National Park of Dadia-Lefkimi-Soufli Forest (Dadia NP, Greece), seven “target” PCBs and 16 organochlorine pesticides (OCs) were analysed in blood samples of cinereous vultures (Aegypius monachus) and Eurasian griffon vultures (Gyps fulvus). PCB congeners 138, 153 and 180 predominated in both species’ blood samples. In both species, no differences were detected in congener levels between successive age classes, but in cinereous vulture, there were significant differences between adult and nestling in levels of PCB 28, 52, 101, 118 and between nestling and immature in levels of PCB 101. Regarding pesticides, p,p′-DDE dominated in both vultures followed by β-HCH, lindane and endosulfan sulphate, but ∑OCs were higher in griffon vulture. Significant differences were detected only between nestling and sub-adult cinereous vultures in heptachlor levels and between nestling and adult in p,p′-DDT. The origin of pollutants differs between the two vulture species and pollution patterns may not reflect those at Dadia NP.

Primary goal of this study was to facilitate the management and conservation of Eurasian black vulture (Aegypius monachus) population on a larger scale than the Dadia-Lefkimi-Soufli National Park (Dadia NP). Range use pattern of this population was studied using an integrated radio-tracking methodology. Various home range (HR) parameters were estimated for the breeding (BS) and non-breeding (NBS) season using minimum convex polygon and fixed kernel estimators and incremental cluster polygon analysis. Various comparisons were made within and between the two seasons and between the different age classes. More activity centres were detected during the BS than the NBS. The overall area used by the vultures was bigger in the NBS than in the BS and the adult individuals used HRs and core areas larger in size than the juveniles. During their foraging the vultures prospected a much wider area than Dadia NP and all showed fidelity to the colony while the juvenile individuals were attached to the natal area. The vultures' foraging behaviour has not been affected by supplementary feeding. Measures have to be taken to preserve the foraging areas that were identified and to prevent rural depopulation and the abandonment of traditional stock-raising practices.

The population of the Eurasian black vulture in the Dadia National Park was nearly extinct in 1979 (26 individuals and 4–5 pairs) and since 1988 it has been the only breeding population in Greece and the Balkans. During the period 1987–2005, the number of breeding pairs increased from 6 to 22. The protection of the nesting sites and the establishment of one supplementary feeding site could have contributed positively to this increase. Overall, during 1994–2005 the number of breeding pairs remained stable but breeding success showed a significant decrease. During this period, two remarkable drops in the number of the breeding pairs were recorded in 1995–1997 and in 2003–2005. Concurrent with these decreases, a considerable number of individual adult fatalities were recorded, caused mainly by the consumption of poisoned carcasses. Poisoning can be considered as one of the main reasons of black vultures mortality in Dadia National Park and the adjacent areas.

The Eurasian black vulture (Aegypius monachus) has experienced a severe decline during the last two centuries and is globally classified as near-threatened. This has led to the extinction of many traditional breeding areas in Europe and resulted in the present patchy distribution (Iberian and Balkan peninsulas) in the Western Palearctic. In the present study, we describe the current genetic status of the European populations using both mitochondrial cytochrome b sequences and nuclear microsatellite markers, comparing with those found in Asia (Mongolia and Caucasus region). Although, mitochondrial (mt)DNA revealed a relatively low genetic variability (haplotype diversity), no evidence of genome-wide genetic erosion exists because nuclear diversity exhibits normal levels and strong differentiation. A highly philopatric dispersal behaviour must be invoked to explain the existence of a clear pattern that revealed by the phylogeographic analysis, which indicates a sharp East-West clinal distribution and an allopatric differentiation. The distribution of mtDNA haplotypes one in the Iberian population and two in Balkan population and the significance divergence at nuclear loci fulfill the definitions of those populations as evolutionary significant units. We discuss how management strategies should aim at the maintenance (or increase) of current genetic variability levels, suggesting that independent conservation plans are urgently required to protect these two breeding European populations from extinction.