Minimum population estimates
The minimum population size as of 2019 included bears identified in 2019, including bears that died in 2019; bears not identified in 2019–2020, but whose presence as of 2019 was inferred by pedigree reconstruction; and bears ≥1 year old, identified not in 2019 but in 2020. The second category included existing bears (i.e., bears identified only before 2019) and hypothetical bears generated by the COLONY software, as described above. In the third category, the age or minimum age of bears was determined based on the year of first genetic identification (i.e., bears identified before 2019 were included), the year when their parent was dead, or on the video data obtained at the time of genetic identification. The combination of a DNA-based parentage analysis and video data taken at the hair-trap site sometimes enabled us to determine the age of young bears (i.e., 0–1 years old) that accompanied their mother. Some bears were confirmed to be ≥1 year old when their DNA was collected, and their body sizes were able to be assessed by the video data. Significant differences in body sizes between 0- and 1-year-old bears enabled us to determine if bears were ≥1 year old, even if information regarding their age was unavailable. This assessment was done only when we could identify the bear in the video clip with 100% confidence. Therefore, bears that had the possibility of being cub-of-the-year were not included in the minimum population size as of 2019.