Large terrestrial mammals increasingly rely on human-modified landscapes as anthropogenic footprints expand. Land management activities such as timber harvest, agriculture, and roads can influence prey population dynamics by altering forage resources and predation risk via changes in habitat, but these effects are not well understood in regions with diverse and changing predator guilds. In northeastern Washington state, USA, white-tailed deer (Odocoileus virginianus) are vulnerable to multiple carnivores, including recently returned gray wolves (Canis lupus), within a highly human-modified landscape. To understand the factors governing predator-prey dynamics in a human context, we radio-collared 280 white-tailed deer, 33 bobcats (Lynx rufus), 50 cougars (Puma concolor), 28 coyotes (C. latrans), and 14 wolves between 2016 and 2021. We first estimated deer vital rates and used a stage-structured matrix model to estimate their population growth rate. During the study, we observed a stable to declining deer population (lambda = 0.97, 95% confidence interval: 0.88, 1.05), with 74% of Monte Carlo simulations indicating population decrease and 26% of simulations indicating population increase. We then fit Cox proportional hazard models to evaluate how predator exposure, use of human-modified landscapes, and winter severity influenced deer survival and used these relationships to evaluate impacts on overall population growth. We found that the population growth rate was dually influenced by a negative direct effect of apex predators and a positive effect of timber harvest and agricultural areas. Cougars had a stronger effect on deer population dynamics than wolves, and mesopredators had little influence on the deer population growth rate. Areas of recent timber harvest had 55% more forage biomass than older forests, but horizontal visibility did not differ, suggesting that timber harvest did not influence predation risk. Although proximity to roads did not affect the overall population growth rate, vehicle collisions caused a substantial proportion of deer mortalities, and reducing these collisions could be a win-win for deer and humans. The influence of apex predators and forage indicates a dual limitation by top-down and bottom-up factors in this highly human-modified system, suggesting that a reduction in apex predators would intensify density-dependent regulation of the deer population owing to limited forage availability.

中文翻译：

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人类塑造的多食肉动物景观中的白尾鹿种群动态。


随着人类足迹的扩大，大型陆地哺乳动物越来越依赖人类改造的景观。木材采伐、农业和道路等土地管理活动可以通过栖息地变化改变饲料资源和捕食风险，从而影响猎物种群动态，但在捕食者群体多样化和不断变化的地区，这些影响尚不清楚。在美国华盛顿州东北部，白尾鹿（Odocoileus virginianus）在高度人类改造的景观中很容易受到多种食肉动物的攻击，其中包括最近回归的灰狼（Canis lupus）。为了了解人类环境中捕食者与猎物动态的控制因素，我们给 280 只白尾鹿、33 只山猫 (Lynx rufus)、50 只美洲狮 (Puma concolor)、28 只郊狼 (C. latrans) 和 14 只狼戴上了无线电项圈。 2016 年和 2021 年。我们首先估计了鹿的生命率，并使用阶段结构矩阵模型来估计其种群增长率。在研究过程中，我们观察到鹿种群数量稳定到下降（lambda = 0.97，95% 置信区间：0.88、1.05），其中 74% 的蒙特卡罗模拟表明种群数量减少，26% 的模拟表明种群数量增加。然后，我们拟合考克斯比例风险模型来评估捕食者暴露、人类改造景观的使用以及冬季的严酷程度如何影响鹿的生存，并利用这些关系来评估对总体种群增长的影响。我们发现，人口增长率受到顶级掠食者的负面直接影响以及木材采伐和农业地区的积极影响的双重影响。美洲狮对鹿种群动态的影响比狼更强，而中食肉动物对鹿种群增长率的影响很小。 最近木材采伐的地区的草料生物量比较老的森林多 55%，但水平能见度没有差异，这表明木材采伐不会影响捕食风险。尽管靠近道路并没有影响总体人口增长率，但车辆碰撞导致了相当大比例的鹿死亡，减少这些碰撞可能对鹿和人类来说是双赢。顶级捕食者和饲料的影响表明，在这个高度人类改造的系统中，自上而下和自下而上因素的双重限制，表明由于饲料供应有限，顶级捕食者的减少将加强鹿种群的密度依赖性调节。