Reintroducing a large carnivore in a human dominated landscape: dynamics of an isolated brown bear population over two decades post-reintroduction

Abstract

Large carnivores have been extirpated from much of their historical range, but conservation efforts have supported their recovery. The brown bear reintroduction in the central Alps represents one such case, yet long-term viability of this population remains uncertain due to its small size, isolation, and increasing conflicts with humans. Using spatial capture-recapture and survival models based on non-invasive genetic data and known bear deaths collected on 222 individuals over 21 years (2003−2023), we assessed spatio-temporal trends in bear density, abundance, survival, and range expansion, accounting for sex and age-specific differences. Results indicate an annual population growth rate of 7.7 %, with a mean density of 1.61 bears/100 km2 in the whole study area in 2023, rising to 2.50 within the area permanently occupied by females. Survival probabilities varied by sex and age, with females showing strong site fidelity and males exhibiting higher dispersal and mortality. Although an ecological barrier hinders eastward expansion and connectivity, the permanent range of females increased by 137 %. Despite growth, the population remains small and vulnerable to stochastic events. Sustained genetic monitoring, improved connectivity, and science-based management will be crucial to balance conservation goals and social concerns, ensuring the persistence of this population in a human-dominated landscap