O'Connell Clare N, Frey Jennifer K
Department of Fish, Wildlife and Conservation Ecology, New Mexico State University, P.O. Box 30003, MSC 4901, Las Cruces, NM 88003, United States.
J Mammal. 2024 Apr 20;105(4):765-776. doi: 10.1093/jmammal/gyae029. eCollection 2024 Aug.
Habitat specialists have been largely overlooked in old-growth pinyon-juniper woodlands, despite specialists exhibiting heightened sensitivity to anthropogenic habitat loss. Furthermore, small mammal relationships within pinyon-juniper woodlands have most commonly been investigated via species abundance or habitat use, rather than habitat selection, thereby providing limited management metrics. We used the Oscura Mountains Colorado Chipmunk () as a model organism to evaluate whether old-growth conditions drive resource selection by small mammals associated with pinyon-juniper woodlands. The goal of our study was to determine resources important to the chipmunk to inform management decisions. We evaluated microhabitat selection by testing a priori predictions based on natural history characteristics of the chipmunk and the woodlands. We grouped predictions into habitat characteristics affiliated with or not affiliated with old growth. We tested predictions under a multistage modeling framework using generalized linear mixed models with a binomial response variable of use versus availability. Probability of selection by chipmunks increased with increasing mean juniper diameter and increasing variation of pinyon diameter and decreased with increased distance to rocky escape terrain and increased mean percent grass cover. Our findings support the classification of the Oscura Mountains Colorado chipmunk as an old-growth pinyon-juniper specialist, as the chipmunk displayed disproportionate preference for old-growth microhabitat conditions. We recommend management policies that conserve old-growth multiage stands of pinyons and junipers. Old-growth conditions near outcroppings, escarpments, and large boulders are of particular conservation concern. Further, thinning resulting in increased grass cover may be detrimental to this old-growth pinyon-juniper specialist.
尽管栖息地专家对人为栖息地丧失表现出更高的敏感性，但在原生矮松-杜松林地里，它们在很大程度上被忽视了。此外，矮松-杜松林地里小型哺乳动物之间的关系，最常见的是通过物种丰富度或栖息地利用来研究，而不是通过栖息地选择，因此提供的管理指标有限。我们以奥库拉山脉科罗拉多花栗鼠（）作为模式生物，来评估原生条件是否会驱动与矮松-杜松林相关的小型哺乳动物进行资源选择。我们研究的目的是确定对花栗鼠重要的资源，为管理决策提供依据。我们通过基于花栗鼠和林地的自然历史特征测试先验预测，来评估微栖息地选择。我们将预测分为与原生林相关或不相关的栖息地特征。我们在一个多阶段建模框架下，使用广义线性混合模型进行预测测试，该模型的二项响应变量为使用与可利用性。花栗鼠选择的概率随着杜松平均直径的增加、矮松直径变化的增加而增加，随着与岩石逃逸地形距离的增加和草地平均覆盖率的增加而降低。我们的研究结果支持将奥库拉山脉科罗拉多花栗鼠归类为原生矮松-杜松专家，因为花栗鼠对原生微栖息地条件表现出不成比例的偏好。我们建议制定管理政策，保护原生的多龄矮松和杜松林。露头、悬崖和大石块附近的原生条件尤其值得关注。此外，导致草地覆盖率增加的疏伐可能对这种原生矮松-杜松专家有害。
