Use of bear's rub trees by mesocarnivores

Rub trees are specific trees that bears mark with their scent to communicate their presence to possible partners or rivals. Adult males have been observed more frequently performing this behaviour especially during the mating season. Rub trees are recognizable from the other trees of the surrounding environment due to being larger or of a different species and because they are usually located along travel routes. Some authors suggested that bear rub trees are also likely to be marked by other species. Here we describe the usage of bear rub trees by mesocarnivores. Remote videos showed that carnivores of the study area marked bear rub trees with urine or scats in 4.5–8.5% of the visits and did so, on average, every 4 days. We run a GLMM to assess the probability of re-marking a tree against the age and type of the previous mark, the species that left it and the tree species, using tree ID and animal species as random factors. For all the species, the existence of a previous mark, regardless of its freshness and the species that left it, was the main driver for marking a tree, with great variability between trees. Results support the hypothesis that bear rub trees may function as a “chemical bulletin board” used by other carnivores. Because rub trees are important for animal communication, forest managers should be informed about their location and encouraged to avoid logging them.