Bearded vultures (Gypaetus barbatus meridonalis) are large and highly specialized birds of prey, unique in both behaviour and adaptation. Looking more like eagles than vultures, they have a distinctive black ‘highwayman’ mask and a beard of stiff, hair-like feathers under the chin, from which they get their name.
They live in the extreme habitat of high-altitude mountain cliffs and breed only once a year in winter in potholes weathered by wind, rain and time. Breeding pairs normally lay two eggs, but only ever raise a single chick. In this behaviour called cainism (from the Old Testament story of Cain and Abel), the older sibling out-competes the younger one within a couple of days of hatching.
Their lifestyle is completely non-invasive to humans, as they are the only bird in the world to live on the unlikely diet of bones. These bones are swallowed whole or, if too large, are dropped from the air onto flat rock surfaces to smash open and access the nutritious marrow within.
Another fascinating behaviour is that they ‘mud bath’. This stains their breast feathers to an iron-oxide rich ochre colour and can even turn their large white eggs golden.
