This year the bearded vulture population in Corsica comprised 4 breeding pairs, the same number as last year, but one of them seems to be a newly established couple that re-used an old nest in a valley that had historically been occupied by the species. Two other adults are sometimes observed together, but no nest was discovered.
Three of these pairs laid eggs – in one case, the eggs were removed by a team from the Parc Naturel Regional de Corse and the VCF, for the captive breeding programme, as part of the conservation programme. The other two pairs failed, one after a 2-3-week-old chick died – unfortunately a very common pattern on the island in the last decade.
The extraction of the eggs – that happened on the 22th February (see photo) – is part of a last-ditch effort to try to prevent the disappearance of this species from the island. After the success of last year’s pilot operation and the transfer of the chick to the captive breeding center in Guadalentín (Spain), a decision was taken to remove the eggs from another pair which had not been successful in the recent past – unfortunately the two eggs removed this year were infertile.
The bearded vulture population of Corsica is the last surviving genetic pool of a former meta-population including Sicily, Sardinia, Corsica and the Alps. Not a single bird of this originally large population survived in captivity until last year´s egg was successfully removed and a young hatched and raised by a foster captive bearded vulture pair.
During the last 25 years the bearded vulture population has been declining in Corsica, with the decline most evident in the last few years – from 10 pairs 10 years ago to the current 4. The number of fledglings has also been very poor – between 0 to 2 fledglings per year. This year the two young fledged in 2013 and 2014 (both marked with tags in the nest) have not been identified. Also, a 1st year bird, unmarked, was observed several times in February/March – is it from Corsica (from an undetected successful breeding?) or from elsewhere?
This current dire situation with this species is mostly caused by 4 main threats:
1. Low genetic variability and inbreeding (the mean number of alleles per locus is much lower than in larger historic and recent populations, and also than in other island populations like the historic Sardinian or the recent Crete population)
2. Mortality due to anthropomorphic reasons (shooting, poison, lead intoxication, etc.)
3. Lack of food resources
4. Stochastic demographic events due to very low number of individuals
An expert group that included local, national and international institutions drafted two years ago an emergency action plan to address the dramatic decrease and secure the surviving of this unique genetic pool. Two main actions have been agreed
1. increase in situ the genetic diversity of this population by restocking with birds coming from the captive breeding network
2. secure in long term the Corsican genetic information in an ex situ program, including Corsican birds in the Bearded Vulture EEP: create a Corsican genetic reserve.
Parallel to these, it was deemed necessary to continue to provide supplementary feeding to the Corsican birds, through a revamped and intensive programme of provisioning food to supplementary feeding sites. In the long term, actions to promote the increase of the wild mouflon population, and also the extensive grazing in the mountains, would be necessary.
Apart from the collection of the egg, the VCF and the PNRC also organized an operation to release two young bearded vultures from the captive breeding network – to reinforce the wild population introducing new genes and consequently to increase the genetic variability of this island population. The two young released last year (Montagnolu and Cimatella) are still alive, and they are regularly observed by the PNRC team – they have roamed wide and far across the island and have spent several weeks in Cap Corse, the northernmost tip of the island, where bearded vultures are not normally seen (see maps of the movements of the two birds in the month of June). This year, the program continues, and two other young (Luna and Ercu) were released on the 3rd June (see photos) – Ercu has already fledged from the hacking platform last week.
These operations were partly funded by the Fondation Prince Albert II de Monaco and the DREAL.