Hyperherbivory in Holocene brown bears (LIN.) of the Rif mountains in northern Morocco

Autores:

Shaymae IKEN

Ana GARCÍA-VÁZQUEZ

Gloria GONZÁLEZ-FORTES

Abdeljalil BOUZOUGGAR

Aurora GRANDAL-D’ANGLADE

Resumen:

This study investigates the trophic ecology and chronology of Holocene brown bears (Ursus arctos) from northern Morocco using stable isotope analysis (δ13C, δ15N), radiocarbon dating, and peptide mass fingerprinting (PMF). New and previously published radiocarbon dates indicate that the assemblages from Hattab II and Kehf el- Hammar cluster within a narrow time window in the Early Holocene (between 11,000 and 10,000 cal BP). A few additional remains from Taforalt were also included, although collagen preservation was limited. Of the 150 analysed samples, 54 yielded well-preserved collagen, providing a robust isotopic dataset. The isotopic results consistently indicate a strongly plant-based diet, with δ15N values lower than those of coexisting ungulates and markedly below those of carnivores. This pattern points to an extreme degree of herbivory, exceeding that of sympatric herbivores and indicating clear trophic separation from both carnivores and humans. Placed within the broader isotopic framework of Ursus arctos, these findings highlight the species' well-known dietary plasticity. In the Rif region, the presence of large carnivores likely favoured the occupation of a low trophic niche by brown bears. The Atlas population thus represents an extreme expression of herbivory within the ecological spectrum of the species, illustrating how trophic strategies can shift in response to local ecological constraints. 

Palaeogeography, Palaeoclimatology, Palaeoecology 697 (2026), art.  113908. https://doi.org/10.1016/j.palaeo.2026.113908

Palabras clave:‍ ‍Atlas brown bear , Stable isotopes, Peptide Mass Fingerprinting (PFM), Holocene, Trophic ecology, Taxon-free paleodiet