Bearded vultures arrive at carcasses after other scavengers have stripped the flesh, and take what is left. Bone is estimated to make up around three quarters or more of the diet. Smaller pieces are swallowed whole; larger limb bones are lifted and dropped from height onto favoured rock slabs, a site known as an ossuary, and the process may be repeated until the bone splits.
Digestion does the rest. Stomach pH is reported to be extremely low, roughly one or below, which dissolves bone over about a day and releases the marrow and mineral content. Young birds take years to become proficient at the drop, which is one reason immatures are more often seen scavenging soft tissue.
The orange colour of many adults is not pigment in the feathers. Birds bathe in iron oxide-rich soil and springs, staining white plumage rust. Whether this is display, hygiene or both is still argued.