Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
Institute for Communities and Wildlife in Africa, Biological Sciences, University of Cape Town, Cape Town, South Africa.
Proc Biol Sci. 2018 Jan 31;285(1871). doi: 10.1098/rspb.2017.2533.
Understanding how human activities influence immune response to environmental stressors can support biodiversity conservation across increasingly urbanizing landscapes. We studied a bobcat () population in urban southern California that experienced a rapid population decline from 2002-2005 due to notoedric mange. Because anticoagulant rodenticide (AR) exposure was an underlying complication in mange deaths, we aimed to understand sublethal contributions of urbanization and ARs on 65 biochemical markers of immune and organ function. Variance in immunological variables was primarily associated with AR exposure and secondarily with urbanization. Use of urban habitat and AR exposure has pervasive, complex and predictable effects on biochemical markers of immune and organ function in free-ranging bobcats that include impacts on neutrophil, lymphocyte and cytokine populations, total bilirubin and phosphorus. We find evidence of both inflammatory response and immune suppression associated with urban land use and rat poison exposure that could influence susceptibility to opportunistic infections. Consequently, AR exposure may influence mortality and has population-level effects, as previous work in the focal population has revealed substantial mortality caused by mange infection. The secondary effects of anticoagulant exposure may be a worldwide, largely unrecognized problem affecting a variety of vertebrate species in human-dominated environments.
了解人类活动如何影响对环境胁迫的免疫反应，可以支持在不断城市化的景观中保护生物多样性。我们研究了南加州城市地区的山猫种群，该种群由于疥癣而在 2002-2005 年间迅速减少。由于抗凝血灭鼠剂 (AR) 暴露是导致疥癣死亡的一个潜在并发症，我们旨在了解城市化和 ARs 对 65 种免疫和器官功能的生化标志物的亚致死贡献。免疫变量的方差主要与 AR 暴露有关，其次与城市化有关。城市生境的利用和 AR 暴露对自由放养的山猫的免疫和器官功能的生化标志物有普遍、复杂和可预测的影响，包括对中性粒细胞、淋巴细胞和细胞因子群体、总胆红素和磷的影响。我们发现与城市土地利用和老鼠药暴露相关的炎症反应和免疫抑制的证据，这可能会影响对机会性感染的易感性。因此，AR 暴露可能会影响死亡率，并产生种群水平的影响，因为之前在重点种群中的研究表明，由于疥癣感染而导致大量死亡。抗凝血剂暴露的次生影响可能是一个在全球范围内广泛存在但尚未被认识到的问题，影响到人类主导环境中的多种脊椎动物物种。
