Very Small Home Ranges of Two Gravid European Brown Bears during Hyperphagia

Simple Summary Paklenica National Park is home to the European brown bear while it is also frequently visited by tourists and home to permanent and semi-permanent residents. The aim of our study was to analyze the use of space of the National Park in autumn. Therefore, we have live captured two brown bears in September 2019 and equipped them with GPS/GSM collars to track their movement pattern and then estimate their home range. We captured two females that were both gravid. We found out that these individuals used very small seasonal home ranges in autumn before denning. Additionally, they almost exclusively showed solitary use of their home range. They nevertheless spent a considerable amount of time close to feeding sites and approached human settlements as close as 4 m while they were mostly active during the night. During the pre-denning stage, most human-bear encounters occur, which is why it is important to offer refugia for the animals from human disturbance. In September 2019, two gravid female brown bears (Ursus arctos) were captured and equipped with GPS/GSM collars in Paklenica National Park (Croatia). Home ranges during hyperphagia were analyzed to describe the spatiotemporal requirements. Mean seasonal home ranges were very small with 9.2 km(2) and 7.5 km(2) (Brownian Bridge Movement Model 95%). During the tracking period, both bears used different territories and showed little to no use of overlapping area. The bears in our study spent a considerable time in proximity of artificial feeding sites, indicating a probable use of these structures as a food resource (mean 15.7% and 30.7%). Furthermore, the bears approached very close to human structures such as 8.9 m and 4.4 m. As most encounters between humans and bears occur during hyperphagia, it is important to offer refugia from human disturbance, especially as the National Park is not only used by residents, but also by tourists. To adapt management according to the animal's needs, further studies should include more individuals from different age and sex classes. Both females were gravid. It remains unclear whether gravidity has an effect on the home range and should be further investigated.

Automated summary

The study in Paklenica National Park revealed that European brown bears exhibit solitary behavior in small seasonal home ranges during autumn, spending time near feeding sites and approaching human settlements. Further research is needed to understand the impact of gravidity on home range and to adapt management strategies for human-bear encounters in the park.