title: Ancient DNA reveals differences in behaviour and sociality between brown bears and extinct cave bears.
abstract: Ancient DNA studies have revolutionized the study of extinct species and populations, providing insights on phylogeny, phylogeography, admixture and demographic history. However, inferences on behaviour and sociality have been far less frequent. Here, we investigate the complete mitochondrial genomes of extinct Late Pleistocene cave bears and middle Holocene brown bears that each inhabited multiple geographically proximate caves in northern Spain. In cave bears, we find that, although most caves were occupied simultaneously, each cave almost exclusively contains a unique lineage of closely related haplotypes. This remarkable pattern suggests extreme fidelity to their birth site in cave bears, best described as homing behaviour, and that cave bears formed stable maternal social groups at least for hibernation. In contrast, brown bears do not show any strong association of mitochondrial lineage and cave, suggesting that these two closely related species differed in aspects of their behaviour and sociality. This difference is likely to have contributed to cave bear extinction, which occurred at a time in which competition for caves between bears and humans was likely intense and the ability to rapidly colonize new hibernation sites would have been crucial for the survival of a species so dependent on caves for hibernation as cave bears. Our study demonstrates the potential of ancient DNA to uncover patterns of behaviour and sociality in ancient species and populations, even those that went extinct many tens of thousands of years ago.
authors: Institute for Biochemistry and Biology, University of Potsdam, 14476, Potsdam OT Golm, Germany. ggfortes14@gmail.com.|Department of Biology and Evolution, University of Ferrara, I-44121, Ferrara, Italy. ggfortes14@gmail.com.|Instituto Universitario de Xeoloxía, Universidade da Coruña, 15081, A Coruña, Spain. ggfortes14@gmail.com.
authors: Gloria G
authors: GG
authors: Fortes
authors: Instituto Universitario de Xeoloxía, Universidade da Coruña, 15081, A Coruña, Spain.
authors: Aurora
authors: A
authors: Grandal-d'Anglade
authors: Institute for Biochemistry and Biology, University of Potsdam, 14476, Potsdam OT Golm, Germany.
authors: Ben
authors: B
authors: Kolbe
authors: School of Archaeology and Earth Institute, University College Dublin, Dublin 4, Ireland.
authors: Daniel
authors: D
authors: Fernandes
authors: "Emil Racoviță" Institute of Speleology, 050711, Bucharest, Romania.
authors: Ioana N
authors: IN
authors: Meleg
authors: Instituto Universitario de Xeoloxía, Universidade da Coruña, 15081, A Coruña, Spain.
authors: Ana
authors: A
authors: García-Vázquez
authors: c/o J. Villarías Instituto de Historia, Consejo Superior de Investigaciones Científicas, 28037, Madrid, Spain.
authors: Ana C
authors: AC
authors: Pinto-Llona
authors: "Emil Racoviță" Institute of Speleology, 050711, Bucharest, Romania.
authors: Silviu
authors: S
authors: Constantin
authors: Depto. de Ingeniería Geológica y Minera, Universidad Politécnica de Madrid, 28003, Madrid, Spain.
authors: Trino J
authors: TJ
authors: de Torres
authors: Depto. de Ingeniería Geológica y Minera, Universidad Politécnica de Madrid, 28003, Madrid, Spain.
authors: Jose E
authors: JE
authors: Ortiz
authors: Institute of Palaeontology, University of Vienna, A-1090, Vienna, Austria.
authors: Christine
authors: C
authors: Frischauf
authors: Institute of Palaeontology, University of Vienna, A-1090, Vienna, Austria.
authors: Gernot
authors: G
authors: Rabeder
authors: Institute for Biochemistry and Biology, University of Potsdam, 14476, Potsdam OT Golm, Germany.|Department of Biology, The University of York, York, YO10 5DD, UK.
authors: Michael
authors: M
authors: Hofreiter
authors: Institute for Biochemistry and Biology, University of Potsdam, 14476, Potsdam OT Golm, Germany. axel.barlow.ab@gmail.com.
authors: Axel
authors: A
authors: Barlow
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D000072441:DNA, Ancient; D004272:DNA, Mitochondrial; D005580:Fossils; D010802:Phylogeny; D012919:Social Behavior; D013030:Spain; D001503:Ursidae / Q000145:classification*
chemical_list: D000072441:DNA, Ancient; D004272:DNA, Mitochondrial
keywords: Ursus arctos; Ursus spelaeus; ancient DNA; extinction; homing; sociality