After a 300-year absence, the northern bald ibis has returned to central Europe, thanks to an ambitious reintroduction project involving human-guided migration. Thirty-six of these critically endangered birds are currently following an ultralight aircraft on a migration route that spans 1,740 miles (2,800 km) from Austria to Spain, a journey that could take up to 50 days.

The initiative, which involves human “foster parents” guiding the birds from a microlight plane, represents the first attempt to reintroduce a migratory species using this method. The aircraft, equipped with a small motor and a yellow parachute, provides the birds with a visual and navigational guide as they travel south.

The northern bald ibis, once native to North Africa, the Arabian Peninsula, and much of Europe, faced extinction in central Europe due to hunting and habitat destruction. For over three centuries, the species was absent from the region, with only small populations surviving in captivity. Recent breeding programs have successfully increased their numbers, but without ancestral migration knowledge, the birds initially struggled to navigate their winter routes.

To address this, chicks are removed from their breeding colonies shortly after hatching and raised by human caregivers to imprint on them. This imprinting process ensures that the birds trust their human guides enough to follow them during migration. This year marks the 17th attempt at guiding these birds, with the current flock having embarked on their journey on August 13 and expected to reach their destination in Vejer de la Frontera, Andalusia, by early October.

Human foster parents, who care for the birds by feeding, cleaning, and nurturing them, establish strong bonds with each individual bird. Upon reaching their wintering grounds, the birds gain independence but retain a connection with their human caregivers, recognizing them years later through a unique ritual greeting.

Since the project’s inception in 2002, the central European population of the northern bald ibis has grown from zero to nearly 300. In 2011, the first bird successfully completed the migration to Bavaria without human assistance. Subsequent generations have continued this migration independently, though the impacts of climate change are forcing adaptations. The migration season is now later, necessitating new routes and posing additional challenges.

The current migration route is 186 miles longer than the previous year’s, reflecting the need to adapt to changing conditions. The project aims not only to restore the northern bald ibis population but also to develop techniques that can be applied to other threatened migratory species. The success of this flagship project underscores the potential for innovative conservation methods in addressing the challenges faced by migratory birds in a changing climate.