SAMC Model Inputs from: Predicting dispersal and conflict risk for wolf recolonization in Colorado

The colonization of suitable yet unoccupied habitat due to natural
dispersal or human introduction can benefit recovery of threatened
species. Predicting habitat suitability and conflict potential of
colonization areas can facilitate conservation planning. Planning for
reintroduction of gray wolves (Canis lupus) to the U.S. state of Colorado
is underway. Assessing which occupancy sites minimize the likelihood of
human-wolf conflict during dispersal events and seasonal movements is
critical to the success of this initiative. We used a spatial absorbing
Markov chain (SAMC) framework, which extends random walk theory and
probabilistically accounts for both movement behavior and mortality risk,
to compare the viability of potential occupancy sites (public lands
>500 km2 to minimally meet wolf pack range area). The SAMC
framework produced spatially explicit predictions of wolf dispersal,
philopatry, and conflict risk ahead of recolonization prior to
reintroduction efforts. Our SAMC model included: 1) movement resistance
based on terrain, roads, and housing density; 2) mortality risk and
potential conflict (absorption) based on livestock presence, social
tolerance, land ownership, and state boundaries; and 3) site fidelity
based on habitat quality. Using this model, we compared 21 public land
units by deriving predictions of: A) relative survival time outside each
site, B) intensity of use and retention time within each site, and C) the
probability of use on adjacent public lands. We also predicted and mapped
potential conflict hotspots associated with each site. Among the units
assessed, a complex of USFS Wilderness areas near Aspen, chiefly the
Hunter-Fryingpan and Collegiate Peaks Wilderness areas, had the best
overall rankings when comparing predictions of each metric. The area
balances high-quality, well-connected habitat with relatively low
livestock density and high social tolerance.  Synthesis and
applications:   Our findings highlight the utility of
the SAMC framework for assessing colonization areas and the capacity to
identify locations for effective proactive management, especially of
conflict-prone species. The flexibility of the SAMC framework enables
predicting likely areas of philopatry and human-wildlife conflict using
spatially-explicit metrics which can improve the success of conservation
translocations and management of species with changing geographic extents.

因自然扩散或人为引入而占据适宜且未被占用的栖息地，可助力受威胁物种的种群恢复。预测定殖区域的栖息地适宜性与冲突潜在性，能够为保护规划提供支持。目前美国科罗拉多州正推进灰狼（Canis lupus）的重新引入规划工作。评估在扩散事件与季节性移动期间，哪些占据位点可最大程度降低人狼冲突概率，对该计划的成功至关重要。
本研究采用空间吸收马尔可夫链（spatial absorbing Markov chain, SAMC）框架——该框架拓展了随机游走理论，可概率性地同时考量动物移动行为与死亡风险——以对比潜在占据位点（面积大于500 km²的公共土地，以满足狼群最小领地需求）的生存可行性。SAMC框架可在重新引入工作开展前，针对栖息地定殖前的灰狼扩散、恋巢行为与冲突风险生成空间显式预测结果。
我们构建的SAMC模型包含三部分：1）基于地形、道路与住宅密度的移动阻力参数；2）基于家畜存在、社会容忍度、土地所有权与州界的死亡风险与潜在冲突（即吸收效应）参数；3）基于栖息地质量的位点保真度参数。
借助该模型，我们对21个公共土地单元开展了对比分析，通过推导以下三类指标的预测值完成评估：A）各位点外的相对存活时长；B）各位点内的利用强度与滞留时长；C）邻近公共土地被利用的概率。此外，我们还对与每个位点相关的潜在冲突热点区域进行了预测与制图。
在所评估的单元中，阿斯彭附近的USFS（美国林务局）荒野区域综合体——主要包括亨特-弗莱潘（Hunter-Fryingpan）与学院峰（Collegiate Peaks）荒野区域——在各项指标的对比中整体排名最优。该区域兼具高质量且连通性良好的栖息地、相对较低的家畜密度与较高的社会容忍度。
综合与应用：本研究结果凸显了SAMC框架在评估定殖区域方面的应用价值，以及其识别可开展有效主动管理位点的能力，针对冲突高发物种尤为如此。SAMC框架的灵活性使其可通过空间显式指标预测恋巢行为与人类-野生动物冲突的潜在区域，从而提升保护移地引种与地理分布变化物种管理的成功率。