100 years after going extinct in the Alps, the bearded vulture is now back to the alpine skies – 40+ established territories and a record number (25!) of wild-born fledged young in 2016, in one of the most celebrated and spectacular wildlife comebacks in recent decades in Europe.
What many do not realise is that at the base of this spectacular result is a captive breeding network managed by the VCF, and that includes 40+ Zoos, animal parks and specialized breeding centers, working with a captive stock of birds to maximize production of naturally reared chicks for release.
One of the routine operations we do every spring in the captive breeding network is the adoption of hatchlings by foster parents. Here´s a tale of one such adoption :
On the 21st of March the last of three chicks hatched this year at the Bearded vulture specialized captive breeding center in Vallcalent (managed by the VCF) could be successfully adopted by an experienced foster pair from Guadalentín Breeding center in Andalusia (managed by the Junta de Andalucia and Fundación Gypaetus).
The chick, with a weight of 400g, had hatched on the 10th of March from the second egg of the old breeding pair from Vallcalent. The mother is a very aggressive bird, and refused six males before pair bonding finally succeed. Its first egg has always to be removed from the nest before she lays the second one because she normally buries it under the wool. Furthermore she reacts very nervously during the hatching process – she usually enlarges the hole with its bill where the chick has pecked the egg shell, and accelerates the whole hatching process. This may provoke hematomas and consequently the chick cannot hatch without help.
This breeding season the first two eggs were removed and incubated naturally by a second breeding pair. On the 6th of February, these two eggs were removed because the pair adopted its own chick, and were incubated artificially. From both eggs a chick hatched but for one of the chicks no more birds were available at the center for adoption because the last potential foster pair at the center stopped to breed a few days before adoption, so it was necessary to transfer the chick to another center. The foster pair in Gualalentín successfully adopted the chick upon its arrival and is now feeding it well.
Bearded vulture chicks display aggressive behavior while they are in the nest which results in the death of the younger sibling. This behavior is “obligatory”, and normally results in the death of the second bearded vulture chick in the wild. To prevent this problem and increase the number of chicks produced and reared naturally, second nestlings in the breeding network (or rejected nestlings like the one above) have to be individually reared by a foster pair.
This is one of the most important tasks of the bearded vulture captive breeding coordinator: keeping a close tab on which pairs have a double fertile clutch and could need a foster pair, and which pairs failed but are still breeding and available for an adoption. Only with intense coordination and communication between the 40+zoos and centers this is possible. The adoptions often require transfer of nestlings between partners and countries. This is only possible by if the VCF receives continuously the breeding results of each pair, so that as soon as the clutch fails the pair can receive dummy eggs so they do not interrupt their breeding behavior and may be used as a foster pair.
The final aim of the bearded vulture captive breeding network is to produce chicks suitable for release, capable to survive in the wild without human help and able to reproduce when they arrive to their sexual maturity. Only natural reared chicks fulfil this aim.
The costs of these transfers of hatchlings between centers are mostly funded by the VCF, but this year we have received a generous grant from the Association Francophone des Soigneurs Animaliers (AFSA) to help with these costs.
The VCF would like to thank AFSA and also the center in Guadalentín where this chick was successfully adopted.