Eloy Revilla, Nuria Selva, Carlos Bautista, Miguel de Gabriel Hernando, Alberto Garcia

As anthropogenic pressures increasingly encroach on natural habitats, humans and bears are forced to share space and resources. Bear species occupy diverse biomes and generally have a broad dietary breadth, facilitating their use of human-modified landscapes and increasing the likelihood of negative interactions with humans. However, type and intensity of these interactions may vary across species, space and time.
We conducted a systematic review of literature focusing on the major forms of negative interactions between humans and bear species worldwide, including agricultural damage, infrastructure damage, vehicle collisions, depredation of domestic animals, and attacks on humans. Our aim was to evaluate patterns in the type, intensity and spatial trends of these interactions across countries and species.
An initial scoping search of English literature (2000–2022) yielded 104 papers revealing a strong reporting bias, with around 40% of the studies conducted in the USA and Japan, and more than 80% focusing on only three of the eight bear species: Brown bear, American black bear and Asian black bear. The most addressed interactions were livestock losses (35% of papers), agricultural losses (32%) and attacks on humans (17%). When looking at the actual number of interactions, however, this ranking varies. For example, data from European studies show that, yearly, brown bears damage around 7 000 livestock heads, but are rarely involved in attacks on humans. After refining our search and accounting for reporting bias, we will explore how documented patterns relate to anthropogenic and environmental drivers, such as human population density, human footprint index, indicators of ecosystem productivity and of temperature.
By providing a comprehensive cross-species global synthesis, our study will help identify key gaps in the current knowledge, future research priorities and provide insights relevant to promote human-bear coexistence at a global scale.