Density and demography of snowshoe hares in central Colorado

Abstract

ABSTRACTTo improve understanding of snowshoe hare ecology in the Southern Rockies and enhance the ability of agency personnel to manage subalpine landscapes for snowshoe hares (Lepus americanus) and lynx (Lynx canadensis) in the region, we estimated snowshoe hare density, survival, and recruitment in west‐central Colorado, USA from July 2006–March 2009. We sampled 3 types of forest stands that purportedly provide good habitat for hares: 1) mature Engelmann spruce (Picea engelmannii)–subalpine fir (Abies lasiocarpa), 2) early seral, even‐aged lodgepole pine (Pinus contorta), and 3) mid‐seral, even‐aged lodgepole pine that had been pre‐commercially thinned. In all forest types and all seasons, snowshoe hare densities were <1.0 hares/ha. During summer, hare densities [±SE] were highest in early seral lodgepole pine (0.20 [0.01] to 0.66 [0.07] hares/ha), lowest in mid‐seral lodgepole pine (0.01 [0.04] to 0.03 [0.03] hares/ha), and intermediate in mature spruce‐fir (0.01 [0.002] to 0.26 [0.08] hares/ha). During winter, densities were more similar among the 3 stand types. Annual survival of hares was highest in mature spruce‐fir (0.14 [0.05] to 0.20 [0.07]) and similar between the 2 lodgepole stand types (0.10 [0.03] to 0.16 [0.06]). Stand attributes indicative of dense cover were positively correlated with density estimates and explained relatively more spatial process variance in hare densities than other attributes. These same attributes were not positively correlated with hare survival. Both density and survival of hares in early seral lodgepole stands were positively correlated with the extent of similar stands in the surrounding landscape. Recruitment of juvenile hares occurred during all 3 summers in early seral lodgepole stands, 2 of 3 summers in mature spruce‐fir stands, and in only 1 of 3 summers in mid‐seral lodgepole. Based on estimates of density and demography specific to each forest type, we conclude that managers should maintain mature spruce‐fir and early seral lodgepole stand types rather than thinned, mid‐seral lodgepole stands to benefit snowshoe hares (and by association lynx) in central Colorado. Given the more persistent nature of spruce‐fir compared to early seral lodgepole, and the fact that such stands cover considerably more area, mature spruce‐fir may be the most valuable forest type for snowshoe hares in the region. © 2014 The Wildlife Society.