Take action on behalf of grizzly bears and their habitat
Each of the maps or graphs and associated captions below can be downloaded as pdf files by clicking on either the graphic itself or the graphic title.
Landscapes of Conflict
These maps and graphs show annual and spatial trends of human-grizzly bear conflict organized around bear depredation on livestock in the Greater Yellowstone Ecosystem (GYE) during 2012-2018. Map (A) shows documented conflicts (red dots) relative to public-land grazing allotments with chronic conflicts (in red), less than chronic conflict (shown in orange), and allotments with none at all (in green). Allotments shaded dark green had been retired. Note the phenomenal concentrations of conflicts in the Upper Green River drainage and Owl Creek Mountains in the southeastern portion of the GYE. Map (B) shows conflicts relative to losses of mature whitebark pine trees during 2002-2009 (shades of tan to burgundy) and sites where bears fed on army cutworm moths (green dots). Conflicts over livestock (a substitute high-quality food when natural foods are lost) were concentrated in areas with high levels of whitebark pine mortality not offset by the availability of moths (both high-quality native foods). Livestock-related conflicts in the Upper Green are shown in (D) as a red line relative to losses of whitebark pine seeds, as a green line. Note the jump in conflicts coincident with terminal losses of whitebark pine seeds. Losses of whitebark pine and resulting increases in bear depredation on livestock led not only to increasing conflicts, but also to increasing numbers of grizzly bears being killed because of these conflicts (in [C] shown in red as a proportion of total grizzly bear mortalities in the GYE).
East Front
These maps and graphs show spatial and temporal patterns of conflicts between grizzly bears and people on agricultural lands along the East Front of the Rocky Mountains in the Northern Continental Divide Ecosystem (NCDE). Map (A) shows the distribution of radio-telemetered grizzly bears (as red dots) along the East Front, aligning with west-east trending riparian corridors (shown as light green). Map (D) shows concentrations of conflicts (as shades of tan to burgundy) that also align with riparian areas along a portion of the East Front (from work done by Seth Wilson). As shown by the pie diagram in (E), most conflicts were associated with bears depredating vulnerable livestock or accessing unsecured foods near people’s residences. Secondary catalysts for conflict included unsecured beehives (a source of honey) and unsecured carcasses of livestock dying from natural causes (i.e., boneyards). Increasing numbers of cattle depredations are shown in (C), with a sharp jump during 2016 coincident with or shortly after marked declines in deer populations (indicated by harvest and population estimates in [B]) and restocking of cattle after reductions in numbers triggered by a pronounced drought during 2013-2015 (shown in the top graph of [C], where PDSI indicates drought severity). In other words, the jump in bear depredations on cattle were very likely driven by changes in comparative availability of two primary sources of meat for bears: mule deer and cattle.
These maps and graphs recount the history and patterns of grizzly bear-human conflicts on agricultural lands in the Blackfoot River drainage encompassing the southern end of the Northern Continental Divide Ecosystem (NCDE). Map (A) shows the spatial pattern of conflicts during 1998-2004 (red dots and shaded areas) that aligned with riparian corridors (shown in green), all of which occurred during a period of escalating conflicts (shown in [B]) associated with colonization of the drainage by grizzly bears. Conflicts dropped dramatically after rigorous and increasingly comprehensive coexistence measures were implemented in 2003 (shown in figure [B], which also highlights one measure that featured removal of carcasses dying from natural causes). There were subsequently few conflicts up until 2018, when numbers jumped back up to the peak experienced during 2003 (D). Notably, this spike followed on the heals of wildfires in nearby forest uplands during 2017 (shown in red in [C]) that removed most bear forage.
These graphics show spatial and temporal patterns of grizzly bear mortalities caused by collisions with vehicles on high-speed highways in the Northern Continental Divide Ecosystem (NCDE), 1997-2018. Map (A) shows the locations of bear mortalities along highways (black dots) differentiated by traffic volume (shaded tan to burgundy), with particularly hazardous corridors highlighted in yellow. Figure (B) shows annual numbers of bears dying from collisions, including the dramatic spike in deaths during 2018. Map (C) focuses on the problematic Highway 93 corridor in the Mission Valley, highlighting the concentration of bear deaths from collisions in areas without highway crossing structures (shown as green dots).