Interview with Dimitar Ragyov about the reintroduction of Saker Falcons into Bulgaria

Date of the interview: 17 January 2010

The Saker Falcon is one of most endangered raptors in Europe. In this interview, Dimitar Ragyov talks about a possible reintroduction project for the species in Bulgaria.

Dimitar Ragyov

Dimitar Ragyov and his dog Kajzer

Markus Jais: What is the current status of the Saker Falcon in Bulgaria? Are there currently any breeding pairs?
Dimitar Ragyov: It is not easy to assess the breeding numbers of a rare species on a huge territory like the whole of Bulgaria. For 4 years now we have been doing surveys in priority places (i.e. past breeding sites and habitats considered broadly suitable with plenty of food and nesting sites) to record the species presence. About 10-15% of Bulgarian territory was explored. In results no breeding Sakers were recorded nor were single birds observed from the field teams. However our colleagues report several bird sightings per year during the breeding season. Unfortunately, when these locations were surveyed in details Sakers were not seen again. It suggests that during the breeding season Bulgaria is occupied by few non-breeding birds from elsewhere (e.g. Central or Eastern Europe). The last successful breeding attempt was recorded in 1997; last active nests were reported in 1998 – unsuccessful breeding; in July-August 2005 a pair and a juvenile were seen in Central Bulgaria, which suggests that the birds were probably nesting somewhere nearby. Our population estimate is 0-3 breeding pairs in Bulgaria.

Markus Jais: Why and how has the population declined during the last decades?

Dimitar Ragyov

Young Saker Falcons in their nest in 1983 (West Bulgaria).
© Taniu Michev

Dimitar Ragyov: It seems to be a trivial story for a raptor decline… The process started decades ago and continued with different intensity through the years.
Up to the middle of the 20th century persecution had a great impact on most of birds of prey. There were government sponsored campaigns for killing raptors. According to official data 70,000 raptors were killed in 1957 alone.
Later on, after World War II, the landscape has been drastically altered. Native grasslands and pastures (preferred Saker habitats) were turned into intensive agriculture lands. The destruction and fragmentation of the habitat is connected with loss of preferred prey species such as European Souslik and various grassland bird species.
However probably the greatest effect on Saker population in the period 1960’s-1990’s (ca. 50 bp) had chemicals such as DDT, Aldrin, Dieldrin and Heptaclor used as pesticides. While the first three were banned in late 1960’s, the Heptachlor were intensively used up to 1990s. As a result, a crash of Saker population was witnessed in the late 1990’s. Organochlorine pesticides were not alone causing damages on Saker population. In the 1970’s there was resurgence in the interest of falconry in Western Europe, which was accompanied by an increased demand for falcons. Falcons were needed not just for falconry but to stock the newly established breeding centres that were being created to meet the demand for falcons from European falconers. The 1970’s and 1980’s saw Saker Falcons and Peregrines being taken from many nests in central and eastern Europe, reducing the breeding success of wild populations that had already been badly affected by pesticides. By the 1990’s the number of these activities increased, as did the frequency of reported nest robberies and trapping. Nest robbery, in an already diminished Saker population, may have been sufficient to reduce the level of recruitment into the breeding population to the extent where it did not compensate for adult mortality rates.

Markus Jais: Are dispersing and wintering Saker Falcons recorded in Bulgaria?
Dimitar Ragyov: Sakers are regularly but rarely seen during the summer/autumn and winter period. Specific studies out of the breeding season have not been implemented up to now. During the last two years Saker observations in Northeast Bulgaria (Dobrdzha and Ludogorie Plateaus) increased considerably. This is due to an increase of observers in the region, which is under constructions of Wind Power Plants. In that regard several dozens of watch points operate during the spring and autumn to record the bird migration. This massive ornithological research resulted in tens of sightings of Sakers during the dispersal period August – October in 2008 and 2009.

Former Saker nesting cliff in Nature Park Vrachanski Balkan Mountains. (West Bulgaria)

Former Saker nesting cliff in Nature Park Vrachanski Balkan Mountains. (West Bulgaria).
© Dimitar Ragyov

Markus Jais: You and several colleagues recently published a study about the feasibility of a reintroduction program for Saker Falcons in Bulgaria. How are the possibilities for the Saker Falcon to naturally recolonise Bulgaria?
Dimitar Ragyov: We considered the possibilities for natural recolonisation within the feasibility study. Currently increasing populations in Central Europe without doubt make a good base to expect natural recolonisation. The main problem point is “When?”.
Long-distance settlement in breeding areas far removed from the area of natal origin has never been recorded in the Saker Falcon and is extremely unlikely to occur in areas without an existing breeding population (as it would require the settlement in a novel area by at least two individuals, male and female, of breeding age). Based on the limited extent of range expansion over the 15 years in Central and Eastern Europe, despite increasing population trends it may be concluded that natural recolonisation of Bulgaria is unlikely within the next couple of decades.
Anyway, we do hope that via reintroduction and reestablishment of local territorial birds we may attract some roaming birds to stay and breed in Bulgaria.

Markus Jais: How should a reintroduction program look like for the Saker Falcon in Bulgaria?
Dimitar Ragyov: There are two main strategies for reintroduction of raptors that proved to be highly successful:

  • Translocation of young birds from viable wild population and
  • Captive breeding and following release of the young birds.

The first one seems to be more efficient but viable populations are not always available. The second one is more expensive but it gives freedom to produce and release higher number of birds. We will try to apply the two approaches in our future reintroduction program. The “hacking” release method was chosen as most appropriate for Saker falcons. A RAMAS population model of hypothetical new established population showed that a release of 20 birds (10 males; 10 females) each year would results with 5 – 8 established pairs within 5 year period. The best area for initial releases is the ridge of the Balkan Mountain which crosses the whole country from west to south.

Markus Jais: What must be done to make the reintroduction a success?
Dimitar Ragyov: The best we can do is to follow the best practices in similar projects, together with the recommendations of IUCN/SSC Reintroduction Specialist Group. The first step is already done – preparation of feasibility study and background research. Next step is the preparation activities, which is ongoing now and include: finding of proper birds (genetically and geographically); public discussion of the project; partnerships creating; obtaining of formal permits for the activities. Release and post-release activities should be done with enough and trained people and sufficient funding. Monitoring of the project is important component (e.g. survival and movements of birds, threats and food supply); we need to be prepared for surprises, to stop or change the methodology if necessary.

Former Saker hunting habitat in Ponor Mountains.

Former Saker hunting habitat in Ponor Mountains (West Bulgaria).
© Dimitar Ragyov

Markus Jais: Is there enough food like Sousliks or medium sized birds for Saker Falcons?
Dimitar Ragyov: Although small mammals and medium sized birds are preferred prey, Sakers take a very wide range of prey species, depending on local availability. Pigeons are the main prey in Czech Republic, Slovakia and Hungary. In Serbia hamsters and pigeons are mainly taken. In Moldova and Ukraine sousliks are still the dominant prey item. European Souslik was the main food during the breeding season in Bulgaria.

Our visual observations showed that currently the pigeons in Bulgaria are much less abundant that they are in Central Europe. However sousliks are still widely distributed mammal across the country and much more numerous compared with those in Central Europe. There are not available investigations on how much and what kind of prey Sakers need to occupy and survive in a given territory. We believe that if an area could support species like Long-legged Buzzards, Eastern Imperial Eagles and Peregrines there must be enough food for Sakers too.

Markus Jais: Are there suitable natural nest platforms like cliffs or nests of other species like eagles or buzzards?
Dimitar Ragyov: There are plenty of suitable nests and ledges in the mountains and mountain foothills in Bulgaria. Stick nests are provided mainly by Ravens and Long-legged Buzzards, which are numerous in the country, but also Golden Eagles and Black Storks. In contrast, in the lowland the nest base seems to be a limiting factor for Sakers. There are only few places where Ravens and Long-legged Buzzards have already colonized, therefore few suitable nests.

Markus Jais: Can artificial nest platforms help and how should they be designed?
Dimitar Ragyov: Here in Bulgaria we do not have big experience with artificial nests for Saker falcons, but they seem to be an effective tool to support a Saker population. Our knowledge comes chiefly from colleagues from Hungary and Slovakia ( Artificial nests have been used successfully in Ukraine and Mongolia too. For instance, in Ukraine about 5% of nest boxes were occupied on the second year after setting them up on electricity pylons. In Mongolia the occupancy rate was impressive with 5% in the 1st year; 8% in the 2nd year and 11% in the third year (
All these countries have real populations and artificial nests were provided within the population range or in vicinity of existing breeding territories. Bulgaria is the first country trying to attract Sakers by artificial nest platforms, not having local population. We would be extremely lucky if any Sakers started using them. Saker nesting on artifacts such as pylons or poles was never recorded here.
Using nest platforms we need to be concerned about the place where they are set up. Lack of natural nests of Ravens and Long-legged Buzzards might mean that other factors (e.g. poisoning or shooting) limit their breeding population, in which case artificial nests would act as an ecological trap for Sakers.

Saker nesting cliff in Ponor Mountains (West Bulgaria)

Former Saker nesting cliff in Vrachanski Balkan Nature Park (West Bulgaria).
© Dimitar Ragyov

Markus Jais: How do you think will people, for example hunters, react to a possible reintroduction?
Dimitar Ragyov: Local people are an important factor for success of the reintroduction. We need to work with local stakeholders before, during and after the release stage.
Hunters are one of the target groups; they are associated in a national and many small local organizations, which make the work with them relatively easier. We have contacted them already on national level through their National Hunter and Angler Union.
In regard of Saker falcon conservation the pigeon fanciers might be a more difficult group to work with. Most of them have a negative attitude to all birds of prey, because the later often cause damages on their pigeons. They are not associated in any strong organization and working with them will probably be a challenge. Our “best” place for initial releases was chosen so to have minimum problems between local raptors and people – in fact no interactions between pigeon breeders and peregrines were recorded during the feasibility study period.

Markus Jais: Do you think stealing of eggs or young in the nest might still be a problem?
Dimitar Ragyov: It might happen incidentally or regularly but rarely in the future. But we are far from the times when it was a profitable business for a group of people. In the past the small number of falconers in Bulgaria used wild taken birds, but today the new generation falconers tend to use birds from legal European breeding facilities. The level of stealing eggs and young is much lower now and it should not have an impact on our project.

Markus Jais: In some countries, escaped hybrid falcons, for example hybrids between Saker and Peregrine or Saker and Gyr Falcon might hybridise with local Saker Falcons. Do you think this might be a problem in Bulgaria?
Dimitar Ragyov: The problem with hybrids is an international issue. It is more relevant for countries with well developed falconry. An international hybrid working group was established few years ago. It aims to assess the potential risk, to evaluate the situation including genetic analyses of wild populations. The number of falconers in Bulgaria is less then 30 people. Some of them own hybrids, and probably some birds escape. However no cases of breeding or pairing of hybrid with falcon have ever been reported from Bulgaria.

Markus Jais: The Saker Falcon is often regarded as an umbrella species. What other species might benefit from it’s reintroduction?
Dimitar Ragyov: Conservation of Saker falcon could induce the protection of other species such as the European Souslik and specific habitats e.g. mountain steppe and pastures and stimulate wildlife friendly agricultural land use. So far we have invested resources and time of studying Sousliks and other raptors species (all of them with high conservation status), which will lead to better protection via decision making process.

Markus Jais: How do you see the future of the Saker Falcon in Bulgaria?
Dimitar Ragyov: According to the European Saker Falcon Action Plan the target population numbers for Bulgaria are as follows: 2010 – 15-20 bp; 2015 – 25-30 bp; 2020 – 50-60. Obviously we are far from following this pattern. The modeling of the new established population showed that if we manage to start releases in 2011 (involving the release of 20 juveniles each year for five years) we would establish an increasing breeding population of between 8 to 15 breeding pairs in 2020. We think that the target numbers for Bulgarian territory in long term aspect could be about 50 pairs which is approximately the number of pairs existed in the second half of 20 century. The restoration should start in the mountain areas and expand to the lowland after detail investigations of the potential negative factors in the agriculture areas.

Markus Jais: What was your most amazing experience with Saker Falcons?
Dimitar Ragyov: The sound of Saker feathers diving on me in Baitag Mountains, China.

And some interesting records:

  • A Saker was hatching Kestrel’s eggs in old Raven nest on electricity pylon in Crimea Peninsula, Ukraine.
  • Pair of Sakers was hatching 7 eggs on an artificial nest in Mongolia (unfortunately the nest failed during incubation).

Markus Jais: Dimitar, thank you very much for the interview.

Further Information

Saker Falcon Reintroduction in Bulgaria Feasibility Study

The project in Bulgaria is within Southeast European Saker Falcon Network (SESN) activities, coordinated by Central Laboratory of General Ecology (CLGE) and financially supported by Environment Agency of Abu Dhabi (EAD) and People Trust for Endangered Species (PTES).