Activity Patterns of the Reintroduced Brown Bears (Ursus arctos) in the Pyrenees Estimated by Photo-trapping Camera

Abstract

Information on intra-specific activity patterns in non-social species, such as the brown bear (Ursus arctos), is important for understanding behavioral strategies of avoidance among individuals, specially between different age-sex classes during the breeding season. These studies are particularly important in small and reintroduced populations that are growing and recovering to apply effective conservation measurements. In this study, we reported the intra-specific activity patterns of the bear population in the Pyrenees (Northern Spain and Southern France), between March 2010 and December 2017, in relation with individual avoidance according to sex (males, solitary females and females with offspring), reproductive class (adults, sub-adults and cubs) and dominant males in the study area (dominant and sub-dominant), using a camera-trap survey. We found strong evidence that activity differed between two reproductive classes, sex and seasons. In general, bears were primarily nocturnal, with crepuscular peaks at 6h and 20h (sundial time); however, we present first evidence for this area suggesting that intra-specific activity differs among individuals as an adaptive behavioral strategy, namely: (1) females with cubs avoid males during the mating season, (2) females with cubs and sub-adults are more diurnal, and (3) the activity periods of solitary females and males is similar. Results revealed a high overlap between the activity pattern of males and solitary females, and also between dominant and sub-dominant bears. Indeed, the overlap between males and females with young, and between adult and sub-adult, was lower. These findings support the idea that in the Pyrenees the temporal segregation of brown bear activity is a behavioral strategy to avoid or support encounters with males, according to the reproductive class, decreasing the chances of infanticide.

1. Activity patterns 2.. Brown bear 3. Pyrenees