Northern bald ibis: Successful launch of second human-led migration to Andalusia

Good news for northern bald ibis conservation and reintroduction in Germany: a few weeks ago, an ultralight aircraft belonging to the Waldrappteam project took off from Lake Waginger to lead 36 young birds to wintering grounds in Spain. The primary goal is to establish a permanent population in the DACH region. To achieve this, the juveniles must be taught the migratory routes to their winter quarters. It‘s a logistical challenge: since mid-August the birds, conservationists and machines have been making their way to Andalusia using an ultralight aircraft, accompanied by a support team on the ground. Soaring alongside the aircraft are hand-raised juveniles, hatched in 2024 at various zoos, who follow their foster parents in flight legs until they reach their wintering grounds 2,800 km away. To prepare for the long journey, the young birds undergo daily flight training for several weeks. The flight legs initially had a distance of 60 km, which gradually increased to 300 km a day.

Given the threat posed by increasingly warmer autumns, the Waldrappteam’s work represents an important contribution to the conservation of many bird species. If the migratory birds start their journey south too late in the autumn due to prolonged periods of warmth, they may no longer be able to find sufficient thermal updrafts later in the year to enable them to fly over mountain ridges to reach their wintering grounds.

Longest route to date for human-led migration

This is the first time that the team and the migratory birds have flown such a long distance. According to project founder Johannes Fritz, the journey to Andalusia will take around 22 daily flight legs of around 130 km. A similar number of days have been planned for breaks and weather-related delays. This year is also the first time that the birds will be guided by just one aircraft.

Each flight requires constant concentration in order not to lose any birds and to avoid dangerous collisions with the aircraft. An additional challenge is local wind currents on this route, for example in the Rhône Valley in the border region of France and Spain, or in the well-known Levante in eastern Andalusia, which can force the pilot to make unplanned landings.

The downsizing to just one aircraft is intended to further optimise the ecological and economical aspects of human-led migration. During the journey, tests will be conducted with another more versatile and cost-efficient aircraft in order to determine the suitability of other models for future reintroduction projects.

Increasing threats to migratory birds

Human-led migration allows the birds to reach their new wintering grounds in Andalusia without crossing alpine barriers. The conservation effort, which is coordinated by Schönbrunn Zoo as part of the second LIFE Programme, aims to compensate for the threat of climate change in order to ensure the long-term survival of the northern bald ibis in Europe.

In previous years, the animals were led to Tuscany to overwinter, which meant crossing alpine ridges. However, due to climatic changes, the team have opted for the ‘natural’ migration route to Spain instead, following the example of the storks, where the birds do not have to cross extremely high mountain ridges.

Since 2010, Hellabrunn Zoo has been supporting the Waldrapp team in their efforts to preserve the northern bald ibis as part of its commitment to species conservation. The collaboration, which involves working towards a common goal of reintroducing the bird species, has helped establish the first self-sufficient breeding colony in Europe in over 400 years. In addition to reintroduction, the project is also dedicated to combating another major threat: illegal hunting. Before release, each bird is fitted with a GPS transmitter, which allows the team to track their movements. This year's migration does not include any Hellabrunn-born young birds.

New reintroduction methods being tested

Johannes Fritz, project manager and Waldrappteam pilot, is convinced that the project’s reintroduction method can also be used for other threatened migratory bird species by adapting migration routes and establishing new populations. In previous years, a total of 277 juveniles were introduced to wintering grounds in Tuscany as part of two EU-funded LIFE Programmes. These juveniles are the founders of a population that now comprises more than 250 birds that migrate from Tuscany to four breeding grounds every year, where they breed and subsequently fly back to Tuscany with their offspring in the autumn. It is the world's first migratory bird population founded by humans.