The role of the Egyptian Vulture (Neophron percnopterus) as a bone accumulator in cliff rock shelters: an analysis of modern bone nest assemblages from North-eastern Iberia

The Egyptian Vulture (Neophron percnopterus) is one of the smallest vultures in the Old World. Today, this vulture is seasonal in Europe, spending winter in North Africa and returning to Europe in spring; however, some permanent populations reside in the south of the Iberian Peninsula and the Balearic Islands. These birds feed mainly on carrion but are opportunistic and will prey on small mammals, birds and reptiles. The remains of Egyptian Vultures have been found on archaeological sites dated to the Pleistocene and Holocene, raising the possibility that they may have been active bone accumulating agents in caves and shelters, a practice evidenced by contemporary observation. Taphonomic studies on prey remains consumed by this vulture are very scarce and its role as an agent responsible for bone accumulations on archaeological sites is not fully understood. In this paper, we analyse bone remains recovered from three well known Egyptian Vulture nests situated in cliff rock shelters from Osona and Ripollès regions (Northeast Spain) with the aim of characterising their accumulations. Specifically, we detail taxonomic and anatomical representation, bone breakage, beak marks and digestion damage. Results show that very diverse taxonomic groups can be accumulated in Egyptian Vulture nest assemblages. The anatomical representation pattern varies greatly depending on the size of prey. Skeletal remains show a low degree of fragmentation and digestion, whilst the proportion of beak marked bones is high. Comparisons with other agents of bone accumulation (birds of prey and terrestrial mammalian carnivores) reveal that the taphonomic signature of Egyptian Vultures differs from most predators.
Ll. Lloveras was funded by a postdoctoral grant (BP-A 00334 2011) from the Secretaria d'Universitats i Recerca Del Departament d'Economia i Coneixement de la Generalitat de Catalunya. Financial support from research projects HAR2011-26193 from the Ministerio de Ciencia e Innovación (MICINN) and SGR2009-1145 from the Generalitat de Catalunya are gratefully acknowledged.