Chanchani Pranav, Noon Barry R, Bailey Larissa L, Warrier Rekha A
Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, 80523, Colorado, U.S.A.
Graduate Degree Program in Ecology, Colorado State University, Fort Collins, 80523, Colorado, U.S.A.
Conserv Biol. 2016 Jun;30(3):649-60. doi: 10.1111/cobi.12633. Epub 2016 Feb 4.
Tiger (Panthera tigris) conservation efforts in Asia are focused on protected areas embedded in human-dominated landscapes. A system of protected areas is an effective conservation strategy for many endangered species if the network is large enough to support stable metapopulations. The long-term conservation of tigers requires that the species be able to meet some of its life-history needs beyond the boundaries of small protected areas and within the working landscape, including multiple-use forests with logging and high human use. However, understanding of factors that promote or limit the occurrence of tigers in working landscapes is incomplete. We assessed the relative influence of protection status, prey occurrence, extent of grasslands, intensity of human use, and patch connectivity on tiger occurrence in the 5400 km(2) Central Terai Landscape of India, adjacent to Nepal. Two observer teams independently surveyed 1009 km of forest trails and water courses distributed across 60 166-km(2) cells. In each cell, the teams recorded detection of tiger signs along evenly spaced trail segments. We used occupancy models that permitted multiscale analysis of spatially correlated data to estimate cell-scale occupancy and segment-scale habitat use by tigers as a function of management and environmental covariates. Prey availability and habitat quality, rather than protected-area designation, influenced tiger occupancy. Tiger occupancy was low in some protected areas in India that were connected to extensive areas of tiger habitat in Nepal, which brings into question the efficacy of current protection and management strategies in both India and Nepal. At a finer spatial scale, tiger habitat use was high in trail segments associated with abundant prey and large grasslands, but it declined as human and livestock use increased. We speculate that riparian grasslands may provide tigers with critical refugia from human activity in the daytime and thereby promote tiger occurrence in some multiple-use forests. Restrictions on human-use in high-quality tiger habitat in multiple-use forests may complement existing protected areas and collectively promote the persistence of tiger populations in working landscapes.
亚洲的老虎（ Panthera tigris ）保护工作主要集中在人类主导景观中的保护区。如果保护区网络足够大，能够支持稳定的集合种群，那么对于许多濒危物种而言，保护区系统是一种有效的保护策略。老虎的长期保护要求该物种能够在小型保护区边界之外以及工作景观内满足其部分生活史需求，这些景观包括有伐木活动和大量人类活动的多用途森林。然而，对于促进或限制老虎在工作景观中出现的因素，我们的了解并不全面。我们评估了保护状况、猎物出现情况、草原面积、人类活动强度以及斑块连通性对印度与尼泊尔相邻的5400平方公里中央特赖景观中老虎出现情况的相对影响。两个观察小组独立调查了分布在60个166平方公里单元内的1009公里森林小径和水道。在每个单元中，小组记录了沿均匀间隔的小径段检测到的老虎踪迹。我们使用允许对空间相关数据进行多尺度分析的占用模型，来估计老虎在单元尺度上的占用情况以及在段尺度上的栖息地利用情况，将其作为管理和环境协变量的函数。猎物的可获得性和栖息地质量而非保护区的指定，影响了老虎的占用情况。印度一些与尼泊尔大片老虎栖息地相连的保护区内老虎的占用率较低，这对印度和尼泊尔当前的保护和管理策略的有效性提出了质疑。在更精细的空间尺度上，与丰富猎物和大片草原相关的小径段老虎栖息地利用率较高，但随着人类和牲畜活动的增加而下降。我们推测，河岸草原可能为老虎在白天提供了躲避人类活动的关键避难所，从而促进了老虎在一些多用途森林中的出现。对多用途森林中高质量老虎栖息地的人类活动限制可能会补充现有的保护区，并共同促进老虎种群在工作景观中的持续存在。
