Interview with Simeon Marin from Green Balkans about the conservation of Eastern Imperial Eagles, Lesser Kestrels and Cinereous Vultures in Bulgaria.

Date of the interview: 16 February 2010

Simeon Marin

Simeon Marin. © Lyubomir Yankov/Green Balkans

Markus Jais: Green Balkans recently started a project on the conservation of Lesser Kestrel, Cinereous (Black) Vulture and Eastern Imperial Eagle. Why where those species chosen? And why Green Balkans?
Simeon Marin: Yes, we recently started the project “Conservation measures for target species of the EU Birds Directive – Lesser Kestrel, Black Vulture, and Imperial Eagle in their main habitats in Bulgaria”, with the financial assistance of the European Regional Development Fund of the European Union and the state budget of the Republic of Bulgaria through Environment OP 2007-2013.
Green Balkans Federation has been working for the conservation and research of the target species since its establishment.
Among the most significant results is the discovery of the first nest of Imperial Eagles in the area of Strandja – Sakar back in 1989. The same border area presently harbors the main population of Imperial Eagles in the country. The first in Bulgaria young Imperial Eagles radio- and GPS/GSM tagged by the team of Green Balkans in 2007 were from the same area, too.
Impressive results have also been achieved for the research and conservation of Black Vultures during the years. In 1993 the team of Green Balkans discovered the first and until now the only confirmed active nest of Black Vultures in Bulgaria for the past few decades. Some 10-12 Black Vultures regularly feed on the artificial feeding site established and maintained by the Green Balkans’ team in the area of Eastern Rodopi Mountains.
The implementation of the present project will be based on the good results achieved throughout the years. That would guarantee achievement of the aims to a great extent.
The project is oriented towards these three raptor species due to their high conservation status.
We combined conservation of 3 species due to fact that they inhabit similar landscapes/habitats. The common feature of these three species is the fact that they all feed in open areas – meadows, pastures and grazing lands. At the same time they are defined by the EEC Birds Directive as a priority species.
Currently the project area is supporting 90% of Imperial Eagle population in Bulgaria. In the past, the last breeding records of Lesser Kestrel and Cinereous Vulture were from same area. And it’s a pityt that we were witnesses of the disappearance of the last Lesser kestrel colony (1990) and the disappearance of a single breeding pair of Cinereous Vulture (1994-95).

Eastern Imperial Eagle family breakfast

Eastern Imperial Eagle family breakfast.
© Picture: Dobromir Dobrinov/Green Balkans

Markus Jais: What is the current population status of those species in Bulgaria and on the Balkan and what are the main threats for each species?
Simeon Marin: The Imperial Eagle is one of the rarest eagles of Europe and Bulgaria w ith more than 30 nesting pairs in the country nowadays, despite being wide-spread in the past. The population trend is increasing. At present the nature conservation community of Bulgaria has localized 20 of these nests and almost 25% of them are found outside of the national protected areas and NATURA 2000 sites. Thus these pairs are really vulnerable and need the conservation, support and research provided within the project.
Main threats to species: stress from population decline, lack of suitable trees to build a nest, intensification of agricultural activities, decline of grazing.
The main “Bulgarian” subpopulation has a “counterpart” in Turkey, from the other side of the border – similar in size, around 20 pairs. In addition to this there is a population in Macedonia (FYROM) – around 20 – 40 pairs, declining. In Serbia 3-5 breeding pairs, declining. In Greece no known breeding pair, still regular observations in adjacent to Bulgaria areas. Single observations in Romania. And that’s all “Balkans” population.

Black Vultures are in an even worse situation, despite being found in almost all mountains of the country in the past. Today the only remaining colony of the species on the Balkans nests in Dadia Reserve, Northern Greece and the birds from this colony regularly visit the area of the Bulgarian Eastern Rodopi in search of food.
Main threats to species: stress from population decline, disturbance (forest, hunting, recreational activities), poisoning with baits against predators, lost of habitat (forestation) and decline of food source due to huge reduction of extensive livestock farming including traditional pastoral’s practice.

Lesser Kestrels were common breeders in settlements, on roof-tops of houses and churches, riparian banks, etc. in the past. These birds were even found in one of the biggest cities of Bulgaria – Plovdiv.
Today the gracious fliers no longer breed in our country and only single vagrant birds can rarely be seen during migration or following flocks of grasshoppers. Number of breeding pairs number in adjacent countries to Bulgaria are: Greece 2000 – 4000 and FYROM 1500 – 3000. Population trends in both countries is declining. In Turkey we have observed flocks of Kestrels and suspect the possible breeding in European part of Turkey. Breeding in Serbia, Bosnia and Herzegovina and Romania is very uncertain, probably extinct already.
Main threats to species: intensification of agricultural activities, use of pesticides, loss of habitats due to decline of grazing.

Artifical nest for Eastern Imperial Eagle

Artifical nest for Eastern Imperial Eagle.
© Lyubomir Yankov/Green Balkans

Markus Jais: What is the goal of the project and what will Green Balkans do to help those species?
Simeon Marin: The main aims and objectives are:

  • support and maintenance of the populations of rare bird species included in the EEC Birds Directive (79/409/ЕЕС) and their habitats
  •  creating conditions for increasing their numbers and restoring their populations in their former habitats
  •  reducing the conflict between the target species and the realization of investment intentions and projects
  •  increasing the nesting success of the breeding Imperial Eagles and Black Vultures
  • improving the conditions for nesting of the target species
  • “ex-situ” activities for restoring the population of the Lesser Kestrel
  • identification of areas from the habitats of the target species sensitive to investment intentions
  • raising the public awareness on the aims and effects of raptor conservation and biodiversity protection in general

Project activities includes:

  • Guarding and supplementary feeding of Eastern Imperial Eagles – focused approach on separate breeding pair. We use in Bulgarian “individual pair approach” which means that each single pair targeted by the project is fed and guardedby a separate field officer all day around. Previously we tried to guard 2-3 nests by one field officer but this again resulted in disappearances pair or youngsters with unknown reasons. And troubles happened when guard is away protecting another nest…. This field season we will implement this “individual pair approach” on 6 pairs: 4 in this EU funded project + 2 from other donor (EURONATUR).
  • Supplementary feeding of Cinereous Vulture in East Rodopi
  • Radio and satellite tracking of Eastern Imperial Eagle and Cinereous Vulture, both young and adults – to distinguish breeding pairs home range, to study movements and temporary settlement areas etc.
  • Providing nesting grounds for target species. In long term perspective – planting suitable native trees. In short term perspective – providing nest boxes for Lesser kestrel and placement of artificial nests for Eastern Imperial Eagle and Cinereous Vulture
  • Identification of potential areas for restoring Lesser Kestrel population (habitat modeling)
  • Discovery of yet unknown nests of breeding pairs of Eastern Imperial Eagle
  • Monitoring of death rate under power lines in vicinity of the target Imperial Eagle’s pairs
  • Establishment of a captive breeding group of Lesser Kestrels and appropriate set of aviaries and vivarium for them

The provided activities should be carried out within a period of 36 months, starting in September 2009 with the formation of the working team and the launch of the main activities.
The project area will comprise the territories of the Derventski Heights, Sakar, the Eastern Rodopi Mountains, part of Strandja, and their adjacent areas, which harbour the main habitats of the three target species. Ex situ activities will take place in the Green Balkans Wildlife Centre in Stara Zagora.

Nest of Cinereous Vulture

Nest of Cinereous Vulture.
© Borislav Borisov/Green Balkans

Markus Jais: Will other species also benefit from the project, for example through habitat protection?
Simeon Marin: By measures undertaken in the project, mainly monitoring and overall protection, all raptors in project area will benefit.
Through tree planting we are restoring Habitats Directive listed habitat – 92A0 Riparian galleries of Salix alba and Populus alba. The habitat itself especially in vast lowlands provides nesting ground for Lesser Spotted Eagle (Aquila pomarina), Black Kite (Milvus migrans), Long-legged Buzzard (Buteo rufinus), White-tailed Eagle (Haliaeetus albicilla), Common Kestrel (Falco tinnunculus), Hobby (Falco subbuteo), Black Stork (Ciconia nigra), Hoopoe (Upupa epops), Roller(C.garrulus), woodpeckers (D.martius, P.viridis, D.maior, D.siriacus, D.medium, D.minor).
Nesting boxes could be occupied by other small falcon species and owls.
The supplementary feeding in East Rodopi will be beneficial also for Griffon Vultures, and all other raptors inhabiting the area. The biggest “winner” though is the Egyptian Vulture (Neophron percnopterus) because up to 30 individuals gather at the feeding site during the summer.

Cinereous Vulture. Visitor from Greece.

Cinereous Vulture. Visitor from Greece.
© Dobromir Dobrinov/Green Balkans

Markus Jais: How has the population of the Cinereous Vulture developed on the Balkans during the last years? Is the population in Greece increasing and are there any known nests outside of Greece on the Balkan?
Simeon Marin: 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 (Scartsi at al,2008).
More detailed information could be obtained from our colleagues from Dadia in Greece. Here is link to their article:
The only known “deviation” was breeding in Bulgaria in 1993 at around 50 km. from the Dadia colony.
No confirmed breeding case elsewhere on the Balkan yet.

Derventski Heights hills

Derventski Heights hills.
© Ivelin Ivanov/Green Balkans

Markus Jais: The Cinereous vulture has been reintroduced to France and another project to reintroduce the species to the Pyrenees in Spain is currently underway. Are there any plans to release captive bred birds in Bulgaria or does Green Balkans hope that they will come back to Bulgaria and other countries on their own from Greece?
Simeon Marin: We could expect re-colonization from France in 50 – 100 years at the earliest! The last scenario you mentioned is the most natural.
The only closer country from which we could expect natural re-colonization is Greece. And this happened back in 1993, when Green Balkans expedition discovered a successful nesting in Bulgaria, after long, nearly one century disappearance of the species from list of breeding avifauna. Anyway such re-colonization is still what we hope for and we work towards making the process sustainable.
Having a single colony in Balkans, on our opinion, is very threatening for the species survival. That’s why in the framework of Balkan Vulture Action Plan after restocking of Griffon Vulture population in Central Bulgaria (Balkan Mountain and adjacent areas) reintroduction of Black and Bearded Vultures will follow. Of course this could be a matter of more than a decade.

Lesser Kestrel - just arrived from Germany

Lesser Kestrel – just arrived from Germany.
© Dobromir Dobrinov/Green Balkans

Markus Jais: You recently placed two artificial nest platforms on high trees to encourage the breeding of Eastern Imperial Eagles? Why are artificial nest platforms important? How should they be constructed to be suitable and safe for the eagles?
Simeon Marin: In 2009 Green Balkans installed a few artificial nests for the species. The nests were mounted on tall trees suitable for nesting, using climbing equipment.
The action was implemented in the area of the Dervent Heights in order to provide nesting sites and support the Imperial Eagles in their breeding attempts.
The studies carried out by the team for the past years show that there are numerous cases when pairs that have occupied territories do not start breeding because of the lack of suitable trees. In most cases these are newly formed and inexperienced pairs. The artificial nests could provide support to these birds. The best period for placement of artificial nests is the autumn/winter season in order to have suitable nesting conditions available at the time of territory occupation and the beginning of the breeding season.
The sites for mounting artificial nests were selected as a result of the tracking of Imperial Eagles tagged with radio transmitters by Green Balkans in 2007. So far, this has been the longest study of the species employing that technology. These efforts resulted in the identification of several territories, where one, two, or more juvenile and non-breeding individuals are recorded on a regular basis. In 2009, in the beginning of the breeding season, Green Balkans’ team put an artificial nest in such an area.
We recorded few cases of nests of Long-legged Buzzard (Buteo rufinus) and Black Stork (Ciconia nigra) occupied by Eastern Imperial Eagles. Though this happens if Long-legged Buzzard nest is not too low and if Black Stork nest is not too hidden in the vegetation.
Generally if a line of trees in open landscape is already selected for nesting by some raptor as Buzzard or Kite it’s a good sign not only for food availability but also for “observation comfort”.
The best place for nests is over 8 m., near to the main trunk, where branches bifurcate, with enough space for take on/off of the eagles. Poplars are common trees that provide such conditions. But of course when there is no choice, you could place the nest on the top of oak, willow or any others.
It’s important to fix the frame for nest strongly, using main trunk and only live branches of the tree in terms to save time and energy for maintenance during the next few years. We also use Vitis vinifera or other lianas branches to conceal the main frame. It creates the impression of an old nest and it is light at the same time.


Lowlands. © Ivelin Ivanov/Green Balkans

Markus Jais: Is Green Balkans working with other organizations in Bulgaria and other countries on the Balkan?
Simeon Marin: We are doing the best to synchronize efforts and respect all Bulgarian expertise in Nature Conservation. We are receiving support of our Ministry of environment and Water as well.
A Balkan face of cooperation is Balkan Vulture Action Plan of which I believe Green Balkans is a strong part.
For long years we are in partnership with EURONATUR and Frankfurt Zoological Society preserving this species.
Last years we made significant progress in Eastern Imperial Eagle researches using radio and satellite tracking thanks to training and help provided by CBD – Habitat of Spain and Spanish Ministry of Environment.
Vogelpark Walsrode in Germany already granted 4 Lesser Kestrels for our captive breeding program.
And back in 2007 Bearded Vultures hatched and raised in a Breeding Centre for Bearded vultures in Austria were granted to us for long term reintroduction program of this emblematic for Bulgarian Nature protection species.
For the conservation of these species in Bulgaria during long period we relied on support of numerous other organizations: Black Vulture Conservation Foundation and Bearded Vulture Conservation Foundation (recently Vulture Conservation Foundation), EECONET Action Fund, People’s Trust for Endangered Species, Fauna and Flora International, Bulgarian Environmental Partnership Foundation, Peace Corps – Bulgaria, Royal Netherlands Embassy in Bulgaria, Association of Avian Veterinarians (AAV).
Finally all colleagues we are working with are not only good experts but very pleasant and friendly persons. Such warm connection makes working with them very inspiring.

Radio tracking in Derventski Heights

Radio tracking in Derventski Heights.
© Gradimir Gradev/Green Balkans

Markus Jais: One question about a different species. What is the current situation of the White-tailed Eagle in Bulgaria and on the Balkan? Is the population increasing as in other countries in Europe?
Simeon Marin: I only have the data from Bulgaria. Twenty years ago the last refugee for White-tailed Eagles was the Danube River with some 3-5 pairs. Later on the first breeding pairs returned to Coastal Strandja Mountain along the Black See. Then more and more often and in bigger numbers we started to register juveniles wintering at big reservoirs’ surroundings. In few years we eagerly observed a change in their plumage into adult. Thus, some 10-8 years ago records of pairs with breeding behavior, juveniles in the end of breeding season became more frequent.
But first “inland” nest was discovered just recently – during the last 3 years – along an inland Tundja River and in vicinity of dam lakes. Just last year a Green Balkans team found 2 of these “inland” nests and started monitoring their breeding success.
The estimated Bulgarian population is 10 – 14 breeding pairs (Nankinov, D. at al., 2004). Trend is increasing.

Markus Jais: What is the opinion about raptors among the public in Bulgaria? Are raptors still seen as a threat or competition?
Simeon Marin: In the wider public “eagles” were always symbol of pride and power. The most risky group continue to be poachers among legal and illegal hunters. There are still a lot of cases of using raptors as flying targets to check shotgun and shooter’s “capability”.
Another usual reason to shoot a raptor is taxidermism, although it’s forbidden by law. Victims of such approach are mainly wintering Buzzards and other raptors.
Some hunters still call raptors “competitors” but I’m not sure if it is a real perception or a joke with conservationists. Nevertheless general ecological culture of hunter’s society in Bulgaria is much higher than in Mediterranean countries. And it’s well known among them that shooting of raptors is persecuted by law.

Sakar Hills

Sakar hills. © Dobromir Dobrinov/Green Balkans

Markus Jais: What else is Green Balkans doing to protect raptors on the Balkan and how can people help. Is it possible to become a member of Green Balkans for people across Europe?
Simeon Marin: Our main wish is to be focused on field activities such as discovering locations of nesting pairs and securing their breeding success – both through guarding and undertaking of administrative measures, monitoring of raptor populations and quick preventive reactions.

Our main target species so far were Eastern Imperial Eagle and Cinereous Vulture with activities like feeding, guarding, monitoring, radio-tracking etc. But in parallel we pay attention to other raptors inhabiting same range such as Black Kite, White-tailed Eagle, Montague’s Harrier, Saker Falcon etc.
During our work we try to keep close contact and to develop understanding in local communities especially among hunters and foresters. For example after discovering a Montague’s Harrier colony we negotiate with farmers for postponing the harvesting date and mobilize authorized institutions to act.

Anyway our long term work is oriented towards Bearded Vulture reintroduction in Bulgaria. The species is a logo of Protected Areas in Bulgaria and symbol of human irresponsibility to Nature because of its extinction in the wild. Thus we follow a long term strategy for returning the species in Bulgaria implementing step by step the Balkan Vultures Action Plan.

Best help to our work would be donation of funds to our activities. We are succeeding to attract projects from various sources. The recent of our big projects are from EU funding. But they always require our own contribution which is extremely difficult to secure and they is a “threshold” for any our ideas. There hasn’t “donation traditions” developed yet in Bulgaria especially not for nature protection. So, financial help of people who understand our situation will be highly appreciated. You can donate here:

Anyone, who agrees with the Organization’s Statutes and Mission, can become a member of Green Balkans. If you decide to join us and become our member, click here:

The project “Conservation measures for target species of the EU Birds Directive – Lesser Kestrel, Black Vulture, and Imperial Eagle in their main habitats in Bulgaria” is implemented by Green Balkans with the financial assistance of the European Regional Development Fund of the European Union and the state budget of the Republic of Bulgaria through Environment OP 2007-2013


Skartsi, Theodora, Elorriaga, Javier N.,  Vasilakis, Dimitris P., Poirazidis, Kostas (2008) Population size, breeding rates and conservation status of Eurasian black vulture in the Dadia National Park, Thrace, NE Greece, Journal of Natural History, 42:5, 345 – 353.

Nankinov, D. at al., Breeding totals of ornitofauna in Bulgaria. Green Balkans, Plovdiv, 2004.

Additional information

Double success in monitoring and conservation of Imperial Eagle in Bulgaria!!!

Green Balkans

Green Balkans Wildlife Rescue Centre

Balkan Vultures Action Plan