Pronounced brown bear aggregation along anadromous streams in interior Alaska

Aggregated use along salmon-bearing (Oncorhynchus spp.) streams is common for coastal brown bears Ursus arctos; however, it much less in non-coastal (interior) environments, especially the Arctic. A concurrent study of GPS-collared interior Brooks Range mountains, northern Alaska, revealed that and their by were more prevalent than previously known. Our goal was to estimate number, gender, species (Ursus using anadromous while salmon present an area northern, Alaska. We deployed single-catch breakaway hair snares on heavily-used bear trails 7 km sections two identify individual animals through DNA genotypes. collected 119 samples from August September 2016 2017 which 31 unique five American black americanus across both streams. Using a capture-with-replacement analysis, we estimated 24 (95% CI: 22–27) used one stream 15 9–35) other. Across streams, detected higher proportion females males, bears, greater relatedness among same stream. The high number these belies overall low densities region, patterns suggests obtain behavioral specialization social learning. 354 industrial road permitted be constructed southern flanks Range, bisecting numerous rivers, including sampled above. Given our findings, potential mitigation measures reduce human-bear conflicts related aggregated