Bearded Vultures in Europe: From Persecution to Protection
Since the early 1900's the Bearded Vulture population in Europe has come under pressure. People used to believe the birds killed livestock like lambs (therefore the name Lammergeier) and even abduct babies. Therefore, numbers dwindled and on several locations the population got extinct. But, since conservation of vultures took off from the early 80's, the European population has made a comeback: one of the greatest comeback stories in conservation.
In 1913, the last Bearded Vultures disappeared from the Alps. Sardinia followed in the 60's, Andalucia in the mid 80's and the Bearded Vulture disappeared from the Balkans in the 2000's. In Europe, only the subpopulations in the Pyrenees, on Corsica and on Crete remained, but those populations were under severe pressure as well. Numbers of those populations were at their lowest around the mid 70's. At this point, people started to realise the importance of vultures for the ecosystem. They are nature's clean-up crew and stop diseases in livestock and wildlife from spreading. So people started to make an effort in conservation. This led to the start of a slow recovery of the Pyreneen subpopulation and the first (unsuccessful) attempt of a reintroduction project in the Alps. One bird escaped in 1975, was seen several times in the area but vanished in the end.
In 1986, the releases started in Austria. This project was well-prepared and became a huge success. Since the start of this programme, 233 birds have been released in the Alps. These birds all came from a captive-breeding programme, which today still exists and is managed by the Vulture Conservation Foundation (VCF). These releases have led to the current population of around 52 territories in 2019, in which 39 wild-hatched youngsters fledged. In the Alps, there are now 3rd and 4th generation wild-hatched birds, which also breed wild-hatched x wild hatched fledglings. During the same period, conservation actions in the Pyrenees also very successful. No birds were introduced here. This lead to a rise in numbers of fledglings around the mid 90's, coming from 39 fledglings in 1994 to 61 in 2015. This means the growth-rate of the number of fledglings is lower in the Pyrenees, but the number of fledglings is still higher than the alpine number.
In 2009, Schaub et al did a population viability analysis on the population of Bearded Vultures in the Alps, which was published in the Journal for Applied Ecology in 2009. They found out that (with data up to 2006), the alpine population has been self-sustaining since 2006. This means releases could cease, without endangering the population if mortality rates would not increase. Nevertheless the decision was made to continue the releases in the Alps, but change the focus of the releases. Releases were no longer focussed on demography or numbers, but on genetics and locations.
As the founding birds of the captive-breeding programme consists of a limited number of birds, the genetic diversity of the reintroduced population is quite narrow. In order to widen that base and to prevent inbreeding in the future, the decision was made to release birds with a specific genetic profile. Descendants of some of the rare bloodlines are since then added to the population. This is being done in Switzerland as the chances of the birds will enter the breeding population are the highest. In another project, in Corsica, young birds are released are being done in order to restock the struggling population there in order to save the original Corsican population.
Another reason for the continuing releases is to re-establish connections. The Bearded Vultures used to be widespread in the mountainous regions in Europe. Although it is a philopatric species (which means they tend to breed in the same area where they fledged), there was gene flow between the different subpopulations in Europe. Gautschi et al (2001) investigated the connectivity of the historic Bearded Vulture populations in Europe. Museum specimen collected between 1850 and 1925 were investigated. The analysis showed there was a subpopulation structure, but that all these subpopulations were connected, with an average migration-rate of 0.94 bird per generation. Some few individuals per generation (which is 18 years in the case of Bearded Vulture) fly from one population to the other for breeding. These migration rates differ between the subpopulations: the migration-rate between the Alps and Sardinia was the highest with 1,62 birds per generation. Alps-mainland Greece was around 1,27 and surprisingly the migration-rate southern Spain-Greece was around 1,08. This proves there was dispersal going on, which even led to breeding. With the philopatric behaviour of the species, this breeding is still a rare event. The philopatric behaviour is also within the Alps not a 100%, but somewhere between 50-70% of the birds return to their fledging location to breed (within a 20 km radius). This implies the portion of non-breeding birds moving between population might even be higher. The gene flow provided by dispersing birds, proves to be vital for the long-term survival of the species (to protect from inbreeding). Therefore, the releases are being done in specific locations in order to reconnect the different subpopulations, using the philopatric behaviour of the species. The releases in the Vercors, Baronnies and Grands Causses re-establish the connection between the Alps and the Pyrenees. In Andalucia and Maestrazgo the connection between the Pyrenees and North-Africa is re-established. In a couple of years’ time the reintroduction in Bulgaria will start in order re-establish a subpopulations in the Balkans. Ultimately, the goal is to re-establish the total European meta-population from North-Africa to Turkey.
Regardless of the low numbers in the previous century, there have always been dispersing birds. There are 7 records of young Bearded Vultures showing up in the Alps during their extinction there (between 1930 and 1986, to keep a period of uncertainty of the extinction in 1913). These birds must have come from elsewhere, like the Pyrenees or Corsica/Sardinia. Besides those, there are records near Bordeaux (1936), Camargue (1973), Allier (1975), Cevennes (1980) and the Belgian Ardennes (1982). The origin of these wild-hatched birds is unknown. Also in Spain, around 130 records exist of Bearded Vultures showing up outside the Pyrenees, in areas where they are formally extinct. After 1986, the year when the releases started in the Alps, there are 18 records of released birds showing up outside the Alps up till 2016. These birds are recognizable by their rings, bleached feathers and GPS-tags. Some birds have never been seen in the field, but their travels are known by their GPS tags. This proves that, even though the bird is huge, it is still easily missed. Besides the reintroduced birds, there are 19 records of wild-hatched birds showing up in (north) Western Europe. The origin of these birds can not be established as they are all unmarked and have similar plumage. In other parts of Europe there are also remarkable records. The island of Cyprus has 5 records, for which the birds had to cross at least 70 km of open sea coming from mainland Turkey and the island of Corfu has a record in 2015, of which the origin of the bird is unknown. Between 1980 and 2012 at least 12 Bearded Vultures where observed on Sardinia, all birds probably coming from Corsica. Specific attention is asked for the proven dispersal of a bird born in the wild in the Pyrenees, that is now breeding for the third consecutive year in the southern Alps. So far unpublished research on the genetic profile extracted from feathers underneath the nest (done by Franziska Loercher (VCF/Stiftung Pro Bartgeier), proves that the geneflow that Gautschi et al. found, is again happening. For the conservation of the species, this is a vital discovery and a major scientific highlight.
The information above is only a short summary of all the information that is available on the ecology and dispersal movements of the Bearded Vultures and of all the conservation actions on this species. Nevertheless, it is clear that the dispersal of young birds is a vital part of their ecology, and that the species has done so during its existence. It also proves that the entire European population is self-sustaining, with some very important pieces of the puzzle to be resolved, in order to further ensure the long term-survival of the species.
The Vulture Conservation Foundation (VCF) is, together with her partners, working hard on the conservation of vultures, with the Bearded vulture as a flagship species. More information on their work is to be found on www.4vultures.org. As you might imagine, these pan-european conservation actions are not easy and ask a big effort, in work and money. Please consider a donation to the VCF, to help save these magnificent birds!
Hans Pohlmann
Vice-president of the Vulture Conservation Foundation
21 July 2020
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