Habitat Use of Autumn Migrating Sora in the Mississippi Flyway

Sora (<i>Porzana carolina</i>) habitat use during autumn migration has been poorly studied resulting in limited information upon which to base wetland management decisions that consider rails and other waterbirds. We performed nocturnal distance-sampling surveys from ATVs on eleven state and federal wetland properties in Missouri from 2012-2015. We examined covariates related to vegetation species percent cover, horizontal structure and water depth to explain Sora density using hierarchical distance sampling models in R package ‘unmarked’. Sora density was related to average water depth, percent interspersion and percent cover of non-persistent moist soil plants. Questions still remain about how the timing of water impacts Sora during autumn migration since peak water depths are not reached till late in migration in the Mississippi Flyway.

黑脸田鸡（Sora，*Porzana carolina*）在秋季迁徙期间的生境利用研究较为匮乏，导致当前缺乏可用于制定兼顾秧鸡类与其他水鸟的湿地管理决策的有效依据。本研究于2012至2015年间，在密苏里州的11处州属及联邦所属湿地地块开展了依托全地形车（ATV）的夜间距离抽样调查。我们借助R语言‘unmarked’扩展包中的层级距离抽样模型，分析了与植被物种盖度、水平结构及水深相关的协变量，以解析黑脸田鸡的种群密度。结果显示，黑脸田鸡的种群密度与平均水深、斑块交错百分率以及非持久性湿生植物的盖度显著相关。目前仍存在相关科学疑问：水体调控时机如何影响秋季迁徙期的黑脸田鸡？鉴于密西西比迁徙通道内的峰值水深直至迁徙后期才会出现。