Disparate home range dynamics reflect nutritional inadequacies on summer range for a large herbivore

The spatial distribution of animals has consequences for nutrition, predator-prey dynamics, spread of diseases, and population dynamics in general. Animals must establish a home range to secure adequate resources to fuel their energetic needs. Home ranges, therefore, are temporally and spatially dynamic given the changing requirements of an animal and the availability of resources on the landscape. We used data from two populations of bighorn sheep with contrasting population dynamics following pneumonia epizootics and different habitat quality on their summer range to test the hypothesis that the distribution and size of home ranges are influenced by environmental conditions and reproductive status. We used a combination of data from 768 vegetation transects and remotely sensed metrics to index forage quality of consecutive biweekly home ranges for 27 bighorn sheep, June–August 2019–2021. There were population differences in space use that were consistent with resource limitations in t..., We used data from two populations of Rocky Mountain bighorn sheep within the Greater Yellowstone Ecosystem in northwest Wyoming, USA, 2019–2021 (Figure 1). The Whiskey Mountain population experienced a pneumonia epizootic in 1991 (Ryder et al. 1992) and has since exhibited population decline via low juvenile recruitment (22 juveniles per 100 adult females in winter on average 2019–2021; Wyoming Game and Fish Department 2021a), leaving the population at ~20% of its former population size (upwards of 1,500 animals; Wyoming Game and Fish Department, unpublished data). The Jackson population experienced pneumonia epizootics in 2001 and 2012 but has been able to recover to previous population size (~ 400 animals) and maintain higher juvenile recruitment (38.6 juveniles per 100 adult females; Wyoming Game and Fish Department 2021b).
Study animals were seasonal elevational migrants. Summer ranges were high-elevation (~3,000m) alpine habitats with alpine meadows, talus fields, and rocky outcrop..., , # Disparate home range dynamics reflect nutritional inadequacies on summer range for a large herbivore

[https://doi.org/10.5061/dryad.44j0zpcmc](https://doi.org/10.5061/dryad.44j0zpcmc)

## Description of the data and file structure

**PCA\_data**
This file contains all the meterics that went into the PCA with varimax reduction. For more detail on exactly how these metrics were quantified see Wagler et al. 2023. Implications of forage quality for population recovery of bighorn sheep following a pneumonia epizootic. Journal of Wildlife Management 87:e22452.
Each metric reflects the mean of that variable for the line point intercept transect.
DMD\_rx = mean dry matter digestibility (%) for each plant along the transect. this metric accounts for for inorganic hits (inorganic hits accounted for in the mean with a 0)
CP\_rx = mean crude protien (%) for each plant along the transect. this metric accounts for inorganic hits (inorganic hits accounted for in the mean with a 0)
Biomass\_kgha\_tr...

# 家域动态差异反映大型植食动物夏季觅食地的营养不足
动物的空间分布总体上会对其营养状况、捕食者-猎物动态、疾病传播及种群动态产生影响。动物需划定家域（home range）以获取充足资源，满足自身的能量需求。因此，鉴于动物的需求随时间动态变化以及景观中资源的可获得性波动，家域在时间与空间维度上均呈现动态特征。我们利用两个大角羊（bighorn sheep）种群的数据开展研究，这两个种群在肺炎流行病（pneumonia epizootics）暴发后呈现出截然不同的种群动态，且夏季栖息地的生境质量存在差异，以此检验"家域的分布与规模受环境条件及繁殖状态影响"这一假说。我们结合768条植被样带（vegetation transects）的数据与遥感指标，对2019-2021年6月至8月期间27只大角羊的连续两周家域的觅食质量进行量化。不同种群的空间利用模式存在差异，这与资源限制的假设相符……

我们使用了2019-2021年美国怀俄明州西北部大黄石生态系统（Greater Yellowstone Ecosystem）内两个落基山大角羊（Rocky Mountain bighorn sheep）种群的数据（图1）。威士忌山种群（Whiskey Mountain population）于1991年暴发肺炎流行病（Ryder等，1992），此后因幼崽补充率低下出现种群衰退：2019-2021年冬季平均每100头成年雌性仅能产下22头幼崽（怀俄明州鱼类与野生动物部门，2021a），当前种群规模仅为原有种群的约20%（原有种群规模超过1500头；怀俄明州鱼类与野生动物部门，未发表数据）。杰克逊种群（Jackson population）分别于2001年和2012年暴发肺炎流行病，但已恢复至原有种群规模（约400头），并维持了更高的幼崽补充率（每100头成年雌性对应38.6头幼崽；怀俄明州鱼类与野生动物部门，2021b）。

研究对象为季节性海拔迁徙物种。夏季栖息地为海拔约3000米的高山生境，包含高山草甸、碎石坡与岩石露头……

[https://doi.org/10.5061/dryad.44j0zpcmc](https://doi.org/10.5061/dryad.44j0zpcmc)

## 数据与文件结构说明

**PCA_data**
该文件包含用于进行主成分分析（PCA，varimax旋转降维）的全部指标。如需了解这些指标的具体量化方法，请参考Wagler等（2023）的研究：《肺炎流行病暴发后大角羊觅食质量对种群恢复的影响》，《野生动物管理杂志》87:e22452。
每个指标代表样带点截距法（line point intercept transect）样带内各植物变量的平均值。
DMD_rx：样带内每株植物的平均干物质消化率（%），该指标会将无机体采样点以0值纳入平均值计算。
CP_rx：样带内每株植物的平均粗蛋白（crude protein）含量（%），该指标会将无机体采样点以0值纳入平均值计算。
Biomass_kgha_tr……