An extensive study in the journal Ecology described layer-by-layer excavations of twelve abandoned bearded vulture nests in Andalusia, Aragón, and Castilla-La Mancha. The work documented nearly seven centuries of material culture and wildlife data.
Between 2008 and 2014, researchers recovered 2,483 objects: 2,117 bone fragments, 86 hooves, 43 eggshell pieces, and 226 human-made or modified items. Artifacts included a late-13th-century esparto-grass sandal, a decorated sheep-leather fragment about 650 years old, a crossbow bolt with a wooden lance, a braided-esparto slingshot, and an 18th-century basket fragment. Radiocarbon analyses dated objects from 150 to 675 years.
Bearded vultures (Gypaetus barbatus) fed mainly on bone, dropping large pieces from height to shatter them. Generations reused the same cliff cavities, piling new branches and debris over old layers. The dry, cool micro-climate sealed organic material away from moisture, so leather, wood, and fiber survived in good condition. Scientists calculated that 9.1 percent of the identifiable remains were human in origin, including 129 cloth scraps, 72 leather pieces, 25 esparto objects, 11 hair samples, and medieval weapons. The anthropogenic material resembled finds from nearby Neolithic caves, suggesting a continuous Mediterranean fiber tradition dating to the Epipalaeolithic.
Chemical screening of eggshell layers aimed to detect pesticide residues that might explain the vultures’ disappearance from southern Spain 70–130 years ago, when persecution, changing agriculture, and declining prey extirpated the species locally.
The bearded vulture is now considered the most endangered vulture in Europe, with an estimated 180–249 individuals in the Mediterranean region and about 309 breeding pairs across the continent. Roughly half live in the Pyrenees. Global numbers stand near 1,675–6,700 individuals. Long-running reintroduction programs that began in the 1970s rely on securing undisturbed, high-quality habitat.
Field teams located the historical nests by reviewing 18th-century naturalists’ journals, interviewing elderly residents who remembered the birds, and using information from rock-climbing biologists. Out of more than 50 mapped nests, the twelve excavated sites had the best structural integrity.
“We have several ideas to analyze in the future. I think that this material will offer a lot of possibilities,” said Antoni Margalida, the study’s lead author, according to National Geographic. The same nests that stored medieval sandals and crossbow bolts may guide modern recovery plans by pinpointing preferred foraging ranges and secluded cliff habitats.
Produced with the assistance of a news-analysis system.