Time Capsules in Feathers and Bone: How Bearded Vultures Became Unwitting Archaeologists

The Accidental Archivists of the Mountains

Long before museums, long before written history in many places, certain cliffs in southern Spain became curators of their own. High in rock shelters once shadowed by circling raptors, the nests of Gypaetus barbatus—the Bearded Vulture—quietly filled with the refuse of both life and death. These birds, known for their habit of carrying bones to high perches and consuming them whole, have an equally unusual penchant for reusing the same nest site for centuries.

A collection of handcrafted materials found in ancient Bearded Vulture nests. Credit: Ecology (2025). DOI: 10.1002/ecy.70191

Now, researchers have discovered that these ancient nests preserve far more than animal remains. They hold fragments of human history.

A study published in Ecology¹ by Antoni Margalida and colleagues from Spain’s Institute for Game and Wildlife Research and the University of Granada examined 12 Bearded Vulture nests in southern Spain, where the species vanished over a century ago. What they found is astonishing: among 2,483 preserved objects—bones, hooves, hair, and eggshells—were 226 artifacts made or modified by human hands. Crossbow bolts, hand-woven sandals, and slingshots of braided grass were nestled among centuries of droppings and feathers.

“These nests function like natural stratigraphic archives,” explains Dr. Laura Sanz, an avian taphonomist at the University of Zaragoza. “They record both ecological interactions and human presence across centuries, in layers as legible as any archaeological tell.”