Evaluating mortality rates with a novel integrated framework for nonmonogamous species.
The conservation of wildlife requires management based on quantitative evidence, and especially for large carnivores, unraveling cause-specific mortalities and understanding their impact on population dynamics is crucial. Acquiring this knowledge is challenging because it is difficult to obtain robust long-term data sets on endangered populations and, usually, data are collected through diverse sampling strategies. Integrated population models (IPMs) offer a way to integrate data generated through different processes. However, IPMs are female-based models that cannot account for mate availability, and this feature limits their applicability to monogamous species only. We extended classical IPMs to a two-sex framework that allows investigation of population dynamics and quantification of cause-specific mortality rates in nonmonogamous species. We illustrated our approach by simultaneously modeling different types of data from a reintroduced, unhunted brown bear (Ursus arctos) population living in an area with a dense human population. In a population mainly driven by adult survival, we estimated that on average 11% of cubs and 61% of adults died from human-related causes. Although the population is currently not at risk, adult survival and thus population dynamics are driven by anthropogenic mortality. Given the recent increase of human-bear conflicts in the area, removal of individuals for management purposes and through poaching may increase, reversing the positive population growth rate. Our approach can be generalized to other species affected by cause-specific mortality and will be useful to inform conservation decisions for other nonmonogamous species, such as most large carnivores, for which data are scarce and diverse and thus data integration is highly desirable.
Vertebrate Zoology Section, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy. simone.tenan@muse.it.
Simone
S
Tenan
Vertebrate Zoology Section, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy.
Aaron
A
Iemma
Vertebrate Zoology Section, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy.|Servizio Foreste e Fauna, Provincia Autonoma di Trento, Via Trener 3, 38100, Trento, Italy.
Natalia
N
Bragalanti
Vertebrate Zoology Section, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy.
Paolo
P
Pedrini
Centre National de la Recherche Scientifique, Laboratoire d'Ecologie Alpine (LECA), F-38000, Grenoble, France.|Université Grenoble-Alpes, Laboratoire d'Ecologie Alpine (LECA), F-38000, Grenoble, France.
Marta
M
De Barba
Laboratorio di Genetica, Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Via Ca' Fornacetta 9, 40064, Ozzano Emilia (BO), Italy.|Department 18/Section of Environmental Engineering, Aalborg University, Sohngårdsholmsvej 57, 9000, Aalborg, Denmark.
Ettore
E
Randi
Servizio Foreste e Fauna, Provincia Autonoma di Trento, Via Trener 3, 38100, Trento, Italy.
Claudio
C
Groff
Vertebrate Zoology Section, MUSE - Museo delle Scienze, Corso del Lavoro e della Scienza 3, 38122, Trento, Italy.|Population Ecology Group, IMEDEA (CSIC-UIB), Miquel Marquès 21, 07190, Esporles (Mallorca), Spain.
Meritxell
M
Genovart
D000818:Animals; D003247:Conservation of Natural Resources; D005260:Female; D006801:Humans; D008962:Models, Theoretical; D010152:Pair Bond; D011157:Population Dynamics; D001503:Ursidae
Ursus arctos; conflictos humanos - animal en conservación; ecología de poblaciones; grandes carnívoro; hierarchical modeling; human-wildlife conflict; integrated population model; large carnivore; modelación jerárquica; modelo de dos sexos; modelo de población integrado; mortality rate; population ecology; tasa de mortalidad; two-sex model