title: Decline and recovery of a large carnivore: environmental change and long-term trends in an endangered brown bear population.
abstract: Understanding what factors drive fluctuations in the abundance of endangered species is a difficult ecological problem but a major requirement to attain effective management and conservation success. The ecological traits of large mammals make this task even more complicated, calling for integrative approaches. We develop a framework combining individual-based modelling and statistical inference to assess alternative hypotheses on brown bear dynamics in the Cantabrian range (Iberian Peninsula). Models including the effect of environmental factors on mortality rates were able to reproduce three decades of variation in the number of females with cubs of the year (Fcoy), including the decline that put the population close to extinction in the mid-nineties, and the following increase in brown bear numbers. This external effect prevailed over density-dependent mechanisms (sexually selected infanticide and female reproductive suppression), with a major impact of climate driven changes in resource availability and a secondary role of changes in human pressure. Predicted changes in population structure revealed a nonlinear relationship between total abundance and the number of Fcoy, highlighting the risk of simple projections based on indirect abundance indices. This study demonstrates the advantages of integrative, mechanistic approaches and provides a widely applicable framework to improve our understanding of wildlife dynamics.
authors.affiliation: Department of Conservation Biology, Estación Biológica de Doñana (EBD-CSIC), C/Américo Vespucio s/n, E41092 Sevilla, Spain isamcano@gmail.com.
authors.forename: Isabel
authors.identifier: 0000-0003-4205-8596
authors.initials: I
authors.lastname: Martínez Cano
authors.affiliation: Dpto. Biología de Organismos y Sistemas, Universidad de Oviedo, C/Valentín Andrés Álvarez s/n, E33071 Oviedo, Asturias, Spain.
authors.forename: Fernando González
authors.identifier: 0000-0002-8263-7501
authors.initials: FG
authors.lastname: Taboada
authors.affiliation: Department of Conservation Biology, Estación Biológica de Doñana (EBD-CSIC), C/Américo Vespucio s/n, E41092 Sevilla, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Naves
authors.affiliation: Department of Conservation Biology, Estación Biológica de Doñana (EBD-CSIC), C/Américo Vespucio s/n, E41092 Sevilla, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Fernández-Gil
authors.affiliation: Department of Ecological Modelling, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318 Leipzig, Germany.
authors.forename: Thorsten
authors.identifier: 0000-0002-3721-2248
authors.initials: T
authors.lastname: Wiegand
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources; D056727:Endangered Species; D004777:Environment; D005260:Female; D011156:Population Density; D011157:Population Dynamics; D012098:Reproduction; D013030:Spain; D001503:Ursidae
keywords: Ursus arctos; environmental forcing; individual-based model; population dynamics; sexually selected infanticide