Factors hypothesized to limit grizzly bear density in interior ecosystems in North America and the variables we derived to index these factors.

Appendix S1 for detailed description of GIS derived variables. We digitized the study area boundary for each study area and calculated the average for each index using a GIS. See Table S1 in = the proportion of the study with pixels rated as >50% herb/shrub.1 This is the sum of all pixels with >the stated percentage of described cover. For example, herb502 This is the mean human and livestock (sheep and cattle) density (summed) for the area within 10 or 50 km of the study area boundary.附录S1包含地理信息系统（GIS）衍生变量的详细说明。我们对每个研究区域的边界进行数字化处理，并通过地理信息系统（GIS）计算各指标的平均值。详见表S1：研究中像元被评定为草本/灌丛覆盖占比>50%的比例¹。该值为所有描述覆盖度高于指定百分比的像元总和。例如，herb502代表研究区域边界10千米或50千米范围内的人类与牲畜（绵羊和牛）密度（求和后）的平均值。