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By Johannes Fritz
Johannes is Project Manager for a LIFE Project to preserve the Northern Bald Ibis in Europe.
Northern Bald Ibises are whimsical birds, with their tuft of iridescent lancet feathers, their bare head with individual black patterns, and their long-curved bill. They are one of the best known and most popular birds in Europe. The species is kept in many zoos throughout Europe, where it is loved by zoo visitors due to the exotic appearance and extraordinary behaviour. But with some luck these birds can also be observed in the wild at some sites in southern Germany, Austria, Switzerland, and Italy.
Just 20 years ago everything was quite different. The species was largely unknown in Europe, absent from collective memory. This is not surprising because the last European birds had disappeared already by the early 17th century. For a long time, Corvus silvaticus, as named and described by the Swiss naturalist Conrad Gessner (1516–65), was considered a mythical creature. Only in the 19th century did ornithologists recognize the correspondence of “Gessner’s fantasy bird” with a species that occurred in the Middle East and Northern Africa (Fritz & Janák, 2022). The first birds to return to Europe came primarily from breeding colonies in the Moroccan Atlas and were destined for breeding in European zoos. Starting with the zoos in Basel and Innsbruck, there has been a successful establishment of breeding colonies in a steadily increasing number of zoos.
At the same time, the wild populations in Northern Africa and the Middle East had been rapidly declining until only a small population remained in Morocco. Hence, the Northern Bald Ibis became one of the most threatened bird species on Earth and was listed on the IUCN Red List as critically endangered in 1994. The prospects for survival in the wild were poor. The size of the last population on the Atlantic coast in Morocco steadily decreased and various attempts at reintroduction were unsuccessful. At that time, hardly anyone would have thought it possible that this species would go on to know success in Europe; yet, today there is a wild, reproductive, and migratory population which has become close to self-sustaining.
The reintroduction project
When our enterprise Waldrappteam Conservation and Research was founded in 2001, hardly anything was known about the ecology and behaviour of this species. Therefore, we had to learn a great deal through trial and error, until it gradually became clear that this species could get a chance to return to Europe as a migratory bird . This turned out to be the first ever successful reintroduction of a migratory bird species, providing new and innovative conservation approaches for migratory birds as an increasingly threatened animal group.
The first European LIFE Project in 2014 marked the beginning of the actual reintroduction. At the closing of this first LIFE Project in 2019, the European migratory population already consisted of 142 birds, divided into three breeding colonies north of the Alps. Based on the success of this project, we received another grant for a seven-year period starting in 2022. This current LIFE Project is being implemented in four European countries by 10 partners under the leadership of Zoo Vienna. It aims at completing the establishment of a self-sustaining, migratory Northern Bald Ibis population in Europe, with seven breeding colonies north and south of the Alps. Our goal is to clearly exceed the minimum viable population size, as defined by demographic modelling, of 314 individuals (Drenske et al., 2021).
We are therefore well on the way to the first ever successful reintroduction of a migratory bird species, but to achieve this goal the major human-caused threats must be reduced. These most especially involve illegal bird hunting in Italy, currently causing about 31% of the losses in Italy, and electrocution on unsecure medium-voltage power poles, accounting for about 45% of all losses. These threats are to be reduced through large-scale campaigns, which we have already launched in the first LIFE Project with some initial successes. For example, a bird hunter was identified and convicted, setting a very important precedent for Italy. Thanks to our campaigns and extensive international media coverage, the Northern Bald Ibis has meanwhile become a prominent and well-known flagship species. We will continue our concerted work to further reduce these anthropogenic threats, which greatly affect many other species as well.
The translocation method
To be awarded such a coveted grant twice is probably the best reference for the value of our project. This not only has to do with the successful reintroduction of this particular species, but also with the fact that we develop, test, and publish innovative conservation methods and thus generate added and broader values.
Our primary and most popular method of release is the human-led migration. It was invented by Bill Lishman, a Canadian naturalist and flight-pioneer. His story was an inspiration not only for the Hollywood film Fly Away Home but also for our team. We applied the method and developed it into an efficient conservation and research tool (Portugal et al., 2014; Fritz et al., 2017; Fritz, 2021).
The methodical basis is hand-raising zoo offspring by human foster-parents, with a resulting “parental imprint.” Because of the close social bonding between the birds and the human foster-parents, fledglings can be habituated to an ultralight aircraft and trained to follow the aircraft with a foster-parent as co-pilot. That’s how after the onset of the migratory readiness (or Zugunruhe), we can lead the juveniles from their breeding grounds hundreds of kilometres to the common wintering area at the WWF reserve Laguna di Orbetello in southern Tuscany. There, they are released and integrated into the ever-growing wild population.
Meanwhile a total of 277 juveniles have been raised, trained, and released in the frame of 15 human-led migrations. In the beginning, flights with 10 birds over 50 kilometres were the norm. Due to methodological improvements, we can now fly with up to 32 birds over distances of as far as 360 kilometres. It turns out that the first-year survival of released juveniles (73%; Drenske et al., 2021) is even higher than that of birds raised in the wild (52%). We were thus able to develop the method, contrary to some criticism, into a comparatively effective means of protecting and restoring this species (the costs for the release by individual are around €7200).
A broader perspective
It is becoming increasingly apparent that climate change is forcing us to broaden the scope of the project. In particular, the onset of the autumn migration is coming later in the year so that the colonies north of the Alps have increasing problems flying over the Alps due to a lack of thermals. That’s why we are currently thinking about establishing a further migration tradition to a second winter area that can be reached by birds from the northern Alpine foothills without crossing the Alpine barrier. One discussed option is to lead our birds over 2000 kilometres to Andalusia and link our population to a sedentary population there, established by a programme called Proyecto Eremita. This would result in a pan-European population, which probably corresponds to the historical ecological reality. The experience generated could significantly expand the scope of possibilities for further conservation projects with other migratory species.
Acknowledgement
The reintroduction of the Northern Bald Ibis is funded with contribution from the LIFE financial instrument of the European Union (LIFE+12-BIO_AT_000143 | LIFE Northern Bald Ibis and LIFE20 NAT/AT/000049 | LIFE NBI).
Rewilding Successes 