Historical range of brown bears

Brown bears (Ursus arctos) are widely distributed in North America, Europe, and Asia; however, their range has decreased. They are categorized as being a species of Least Concern by the International Union for Conservation of Nature (IUCN) red list, but some fragmented, small populations are close to extirpation. Importantly, the global historical range of brown bears is poorly documented, therefore, we reconstructed and estimated their historical range (∼1,000 yr ago). We also analyzed protected areas in their past and current ranges. We retrieved data on the occurrence of brown bears from the literature and used Google Earth Pro software to obtain the coordinates of locations to reconstruct their historical range. Data on the species' current range were obtained from the IUCN red list. Analyses showed that the range was larger in historical times, encompassing 52.16 million km2 area as compared with its current range of 30.7 million km2, resulting in a range contraction up to approximately 41.2%. In the past, 49,118 protected areas covering approximately 3.5 million km2 were present in the species' range but as a result of range contraction, the current range includes only 18,300 protected areas covering approximately 2.3 million km2. The brown bear range in protected areas has contracted by about 34% (1.2 million km2) indicating that even the protected areas have not functioned to maintain their range.