Northern bald ibises were native to Central Europe until the 17th century, but disappeared due to excessive hunting. Efforts have been made to reintroduce the birds to Europe for over 20 years, and around 200 animals are now living in the European Alps once more. In the specialist journal “Oryx” the success of an Austro-German resettlement project is now rated positively: the population shows good survival and reproduction rates and is well on the way to self-preservation.
In 2012, a project for the reintroduction of the Northern Bald Ibis (Geronticus eremita) in the Alps, funded by the EU in the “LIFE Programme”, emerged from a Waldrapp project at the Konrad Lorenz Research Center in Grünau im Almtal (Upper Austria). Since the previous year, this has been followed by the second project “LIFE20: Northern Bald Ibis”, which will run until 2028. It is managed by Schönbrunn Zoo and in which ten partners from Germany, Austria, Italy and Switzerland are cooperating.
The basis for these efforts are young northern bald ibises from breeding programs in zoos. “The chicks are raised by human foster parents and trained to follow an ultralight aircraft with foster parents as co-pilots. In this way, the young birds are guided to the wintering area in the autumn, where they are released into the wild,” explains Johannes Fritz, director and founder of the Austrian “Waldrap Team Conservation and Research”. The Austrian biologist led the birds over the Alps to Italy around 20 years ago as a pilot of a light aircraft.
The population released in this way has been reproducing successfully since 2011 and currently includes around 200 individuals in the colonies of Burghausen in Bavaria, Kuchl in Salzburg, Überlingen on Lake Constance and the youngest colony in the Rosegg animal park in Carinthia, as Fritz explained to the APA. To date, 250 wild young birds have grown up in the colonies.
Since the project began, a large amount of data has been collected on hundreds of birds in the population, which Fritz and his team have now evaluated together with the Leibniz Institute for Zoo and Wildlife Research in Berlin and used it to model future scenarios. According to this, the survival rate for wild hatched birds in the first year was 52 percent, for released young birds 73 percent. Of the adult birds, four out of five survive (78 percent). According to the researchers, these are “good values” compared to other colonies and the last wild population in Morocco.
They rate the reproductive rate as “outstanding” with an average of 2.15 fledglings per nest. “This reproductive success is well above the values of most wild populations and zoo colonies. We attribute this to the rich food supply in the breeding areas,” says Fritz.
An analysis of the population’s survivability showed that it was well on the way to self-preservation. Even environmental disasters such as the hurricane that killed 27 northern bald ibises in just one night in November last year can be compensated relatively well by the current population.
The aim of the current project is to let the population grow to more than 350 individuals, “then they should be able to survive on their own”. On the one hand, further releases into the wild are planned, on the other hand, new colonies will be founded in Switzerland, on the southern edge of the Alps and also in the Salzburg region.
In addition, human-caused mortality must be reduced in the coming years. With 40 percent of the losses, electrocution on unsecured power poles is by far the most common cause of death among the northern bald ibis, emphasized Fritz. In addition, there is illegal bird hunting in Italy. The biologist refers to Germany, where since 2016 electricity pylons have had to be secured by legal requirements. “Since then we haven’t lost a single bird there.”
In Austria, there is cooperation with power grid operators in Upper Austria, Salzburg and Carinthia to secure high-risk masts in the breeding areas. However, these are only regional measures, a nationwide regulation is not yet in sight in Austria. This would not only make a “decisive difference” for northern bald ibises, but also for eagle owls and other large bird species such as storks, red kites and buzzards, there are high losses from electrocution.
A more thorough assessment of the effects of climate change is also important. The beginning of the autumn migration of the northern bald ibis is gradually being delayed, which is probably due to the increasingly mild temperatures in late autumn. As a result, the birds would have increasing problems crossing the Alps, presumably due to a lack of supporting thermals.
(SERVICE – publication: project website:
