While you are about to eat your Easter eggs – chocolate and almond are our favorites!, we have been busy in the last weeks tending to the 42 breeding pairs of bearded vultures (3 more than last year) within our captive-breeding network, managed by the VCF under the auspices if the European Association for Zoos and Aquaria (EAZA) – which is at the base of all our reintroduction and reinforcement projects.
Staff from the VCF and its many partners, both in bearded vulture captive breeding units and in many zoos, have been following the breeding of this species. This year a total of 68 eggs were laid (1 more than last year) – each one very valuable, much more so than the Easter eggs you have just eaten! From those, at least 39 were fertile, and 30 chicks hatched – 4 in the Haringsee specialized breeding center (Austria), 9 in Guadalentin (Spain), and 5 in Vallcalent (Spain), with the remainder 12 in the different zoos in Germany, Czech Republic, Switzerland, Bulgaria, and Armenia.
7 of these chicks have unfortunately died, so right now we have 23 chicks being reared by their parents – are waiting for 7 eggs to hatch. We hope we can get at least 1-2 young more form those – most of those come from new pairs and may be infertile. But in the end, we will not break a record, and the breeding season will only be average – partially because we will need to keep some birds for captive-breeding to address a sex imbalance.
The breeding season has been, as usual, eventful, and our staff have had to deal with multiple events. We are trying to analyze in detail why did some of the hatched chicks died, in order to improve. One of them died probably due to a yolk sack infection, while another – already 5 weeks old – succumbed a few days after a blood sample for sex determination was extracted - the first time in this breeding program that something like that occurred.
One chick also died in the always arduous process of “adoption” – when a chick from the second egg or from a pair with unusual behavior is given to foster parents for rearing. This happened in Vallcalent where a double adoption was done for the first time by one pair. Alex llopis, who is managing the captive-breeding programme, describes the situation: “The pair was rearing successfully a 4-weeks old chick. Because we needed a foster pair for a second chick, a second nest was built in the platform, where this 4-weeks old chick was transferred. In the main nest we introduced the 1-week old chick. Both adult birds immediately adopted it and the female fed both chicks. Next day, however, the male didn’t bring up food to the nest and the bigger chick started to chirp intensively for food - this probably stressed the female. Finally, she took the “weaker chick” (the younger) and tried to feed it the older. Our staff reacted immediately but arrived too late: the female was just tearing the left wing and was giving it to the older chick. It’s the first time in 40 years breeding this species in captivity that this kind of accident happened”. This highlights how small things and disturbances can provoke “disasters” and you cannot have all under control. We never stop learning. Each pair is a new challenge!
But we have also good news! This year 6 news pairs have laid for the first time - 5 laid a single clutch (Prague and Belgrade zoos, Parco Natura Viva, Vallcalent and Haringsee). Unfortunately, all five clutches broke (usual in new pairs), but in three of them the eggs were fertile, giving us hopes that next year they can produce descendants. One of the most exciting events was that the female from Parco Natura Viva (Italy) has laid without problem, after undergoing last breeding season surgery because of egg obstruction. The 6th new breeding pair is coming from Beauval zoo (France). She has laid a double clutch and is still incubating. The male has just become 5 years old. Further a few new birds have started to show breeding behavior, with several mating attempts, in Prague zoo and in the Vallcalent breeding center.
Many people will be working throughout the Easter weekend to make sure these bearded vulture chicks survive - and are available for reintroduction somewhere in Europe. Restoring the species across our mountains - as we have been able to do in the Alps and Andalusia – starts there too! Happy Easter – and enjoy your eggs!