New threats in the recovery of large carnivores inhabiting human-modified landscapes: the case of the Cantabrian brown bear (Ursus arctos)

• Published in: Veterinary Research
• Main Authors: Balseiro, Ana, Herrero-García, Gloria, García Marín, Juan Francisco, Balsera, Ramón, Monasterio, Juana María, Cubero, David, de Pedro, Gabriel, Oleaga, Álvaro, García-Rodríguez, Alberto, Espinoza, Israel, Rabanal, Benjamín, Aduriz, Gorka, Tuñón, José, Gortázar, Christian, Royo, Luis José
• Other Authors: Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), European Commission, Principado de Asturias, Junta de Castilla y León, Universidad de León, Balseiro Morales, Ana María
• Format: Article in Journal/Newspaper
• Language: English
• Published: BioMed Central 2024
• Subjects: Ursus arctos; Brown bear; Infectious diseases; Pathology; Traumas; Wildlife mortality; Protect; restore and promote sustainable use of terrestrial ecosystems; sustainably manage forests; combat desertification; and halt and reverse land degradation and halt biodiversity loss
• Online Access: http://hdl.handle.net/10261/365679; https://doi.org/10.1186/s13567-024-01279-w; https://api.elsevier.com/content/abstract/scopus_id/85186155605

17 páginas, 6 figuras, 3 tablas. Understanding mortality causes is important for the conservation of endangered species, especially in small and isolated populations inhabiting anthropized landscapes where both natural and human-caused mortality may hinder the conservation of these species. We investigated the mortality causes of 53 free-ranging brown bears (Ursus arctos) found dead between 1998 and 2023 in the Cantabrian Mountains (northwestern Spain), a highly human-modified region where bears are currently recovering after being critically threatened in the last century. We detected natural traumatic injuries in 52.63% and infectious diseases in 39.47% of the 38 bears for which the mortality causes were registered, with 21.05% of these cases presenting signs of both infectious diseases and traumas. More specifically, almost 30% of the bears died during or after intraspecific fights, including sexually selected infanticide (10.53%). In addition, primary infectious diseases such as infectious canine hepatitis, distemper, clostridiosis and colibacillosis caused the death of 15.79% of the bears. The number of direct human-caused deaths (i.e., shooting, poisoning, snare) decreased over the study period. This study also reveals three new mortality causes triggered by pathogens, two of which-Clostridium novyi and verotoxigenic Escherichia coli-not previously described in ursids, and the other one, canine distemper virus, never reported in brown bears as cause of death. New management strategies for the conservation of Cantabrian bears, which are urgently needed due to the rapid expansion of the population, should consider the mortality causes described in this study and must promote further research to elucidate how the high prevalence of infectious diseases may threaten the current recovery of the population. This work is a contribution to the I+D+i research projects: 1) PID2022- 141906OB-C21 and PID2022-141906OB-C22 funded by MCIN/ AEI/1013039/50110 0 011033/FEDER, UE; B) PCTI 2021–2023 (GRUPIN: IDI2021000102) ...