Integrating opportunistic and structured non-invasive surveys with spatial capture-recapture models to map connectivity of the Pyrenean brown bear population

• Published in: Biological Conservation
• Main Authors: Kervellec, Maëlis, Milleret, Cyril, Vanpé, Cécile, Quenette, Pierre-Yves, Sentilles, Jérôme, Palazón, Santiago, Jordana, Ivan Afonso, Jato, Ramón, Elósegui Irurtia, Miguel Mari, Gimenez, Olivier
• Other Authors: Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Sud )-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Montpellier (UM), Norwegian University of Life Sciences (NMBU), Service conservation et gestion des espèces à enjeux (OFB SEE), Direction de la recherche et de l’appui scientifique (OFB - DRAS), Office français de la biodiversité (OFB)-Office français de la biodiversité (OFB), Generalitat de Catalunya, Gobierno de Navarra (SPAIN), Financial and logistical support for this study was provided by the ONCFS and OFB-DRAS-SEE in France., ANR-16-CE02-0007,DEMOCOM,Effets de la gestion et du climat sur la dynamique des communautés - Développement d'une démographie multi-espèce.(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: Fragmentation; Functional connectivity; Large carnivore; Non-invasive genetic sampling; Ursus arctos; Road network; [SDE]Environmental Sciences
• Online Access: https://hal.science/hal-03973407; https://doi.org/10.1016/j.biocon.2022.109875

International audience Connectivity, in the sense of the persistence of movements between habitat patches, is key to maintain endangered populations and has to be evaluated in management plans. In practice, connectivity is difficult to quantify especially for rare and elusive species. Here, we use spatial capture-recapture (SCR) models with an ecological detection distance to identify barriers to movement. We focused on the transnational critically endangered Pyrenean brown bear (Ursus arctos) population, which is distributed over Spain, France and Andorra and is divided into two main cores areas following translocations. We integrate structured monitoring from camera traps and hair snags with opportunistic data gathered after depredation events. While structured monitoring focuses on areas of regular bear presence, the integration of opportunistic data allows us to obtain information in a wider range of habitat, which is especially important for ecological inference. By estimating a resistance parameter from encounter data, we show that the road network impedes movements, leading to smaller home ranges with increasing road density. Although the quantitative effect of roads is context-dependent (i.e. varying according to landscape configuration), our model predicts that a brown bear with a home range located in an area with relatively high road density (8.29 km/km2) has a home range size reduced by 1.4-fold for males and 1.6-fold for females compared to a brown bear with a home range located in an area with low road density (1.38 km/km2). When assessing connectivity, spatial capture-recapture modeling offers an alternative to the use of experts’ opinion when telemetry data are not available.