The Zurich Zoo in Switzerland has announced the release of three more northern bald ibis birds into the wild in July in order to support their comeback on the old continent.
Through participating in several conservation programs the Zurich Zoo in Switzerland is contributing towards a project to revive the northern bald ibis species in Europe after they were eradicated from the continent in the 17th century.
The northern bald ibis, also known as the waldrapp (Geronticus eremita), has been listed as endangered on the IUCN Red List since 2018, after several reintroduction programmes helped to downlist the species from Critically Endangered.
In a statement, Zurich Zoo officials said: ‘Once widespread in the Middle East, North Africa and Central Europe, the bald ibis is now one of the rarest birds. In Central Europe, humans exterminated the bald ibis around 400 years ago.’
European zoos have been raising waldrapps since the 1930s and currently, there are an estimated 1700 of them across a variety of zoos on the continent.
There are currently two resettlement projects being carried out in Europe which are the “Waldrapp Team” project that is working in Central Europe and a second project which is centred in the Southern Spanish province of Andalusia.
The Zurich Zoo is taking part in both projects and has so far released a total of 13 waldrapps into the wild, and they are aiming to release a further three birds next month (July).
According to the zoo, sightings of the northern bald ibises have become increasingly frequent ever since a total of 286 birds were released into the wild by the Waldrapp Team from 2004 to 2018.
Nevertheless, follow-up research found that the mortality rate of the young birds is high, meaning many of the released birds never make it to adulthood or have offspring.
The waldrapp is an unusual bird as in some cases it is migratory and in others sedentary – depending on where they live. The Central European birds migrate to Southern Europe for the winter whilst the population in Spain stays put.
Bald ibises feed on small insects and occasionally rodents, often with life spans of between 20-25 years.
Waldrapp couples are monogamous during the breeding season and raise their young together but may change partners after the breeding season is over.
The animal keepers have welcomed four young waldrapps that hatched at Zurich Zoo this spring.