The return of the bearded vulture

A success story with obstacles

Bartgeier mit ausgebreiteten Flügeln läuft auf felsigem Boden.
This beautiful bearded vulture shows no visible defects but could still be a carrier of the genetic mutation.

Hunted, poisoned, eradicated: the bearded vulture disappeared from the Alps for more than 70 years. Since the 1980s, it has been reintroduced across the Alpine region. The success is visible: today, numerous pairs are once again breeding in the Swiss Alps, and the growing numbers are promising.

But their comeback could be at risk. All of today's birds descend from just a few founder pairs. Genetic diversity is still low, and inbreeding is a real danger.

Since 2009, flightless individuals with malformed feathers have been observed. The cause is likely a genetic defect that manifests under inbreeding.

How inbreeding works

Infographic illustrating genetic variations with symbols representing healthy and harmful copies. Healthy copies are marked with red, harmful copies with yellow, and male and female symbols are shown.

When two animals that share common ancestors mate, the probability increases that both carry the same harmful gene variant. If an offspring inherits this gene variant from both parents, the harmful trait can be expressed.

In bearded vultures, for example, it is assumed that a harmful gene variant leads to malformed feathers when the healthy gene variant is missing. The affected birds are unable to fly.