RT Journal Article SR Electronic T1 Shrinking of the endangered brown bear Ursus arctos distribution in the French Pyrenees revealed by dynamic occupancy modeling JF bioRxiv FD Cold Spring Harbor Laboratory SP 075895 DO 10.1101/075895 A1 Blaise Piédallu A1 Pierre-Yves Quenette A1 Nicolas Bombillon A1 Adrienne Gastineau A1 Christian Miquel A1 Olivier Gimenez YR 2016 UL http://biorxiv.org/content/early/2016/09/19/075895.abstract AB The Pyrenean brown bear (Ursus arctos) in the mountainous border between France and Spain is one of the smallest and most endangered populations of large carnivores in Europe. Here, we aimed at assessing trends in brown bear distribution in the Pyrenees and determining the underlying environmental and anthropogenic drivers. Using detection/non-detection data collected between 2008 and 2014 through non-invasive methods, we developed occupancy models to investigate the dynamic of brown bear distribution in the Pyrenees through local colonization and extinction processes. Our results showed a negative correlation between human density and bear occupancy in agreement with previous studies on brown bear habitat suitability. We found two non-connected occupancy cores, one located in the West and another in the Center of the Pyrenees. Importantly, we showed that the population distribution significantly decreased between 2008 and 2014, and that while bear went locally extinct in some areas, there was no sign of colonization of new ones.