A secure future? Human urban and agricultural land use benefits a flightless island-endemic rail despite climate change

Identifying environmental characteristics that limit species’
distributions is important for contemporary conservation and inferring
responses to future environmental change.  The Tasmanian native
hen is an island-endemic flightless rail and a survivor of a prehistoric
extirpation event. Little is known about the regional-scale environmental
characteristics influencing the distribution of native hens, or how their
future distribution might be impacted by environmental shifts (e.g.,
climate change). Using a combination of local fieldwork and species
distribution modelling, we assess environmental factors shaping the
contemporary distribution of the native hen, and project future
distribution changes under predicted climate change. We find 37.2% of
Tasmania is currently suitable for the native hens, owing to low summer
precipitation, low elevation, human-modified vegetation, and urban areas.
Moreover, in unsuitable regions, urban areas can create ‘oases’ of
habitat, able to support populations with high breeding activity by
providing resources and buffering against environmental constraints. Under
climate change predictions, native hens were predicted to lose only 5% of
their occupied range by 2055. We conclude that the species is resilient to
climate change and benefits overall from anthropogenic landscape
modifications. As such, this constitutes a rare example of a flightless
rail to have adapted to human activity.

明确限制物种分布的环境特征，对于当下的物种保护工作以及推断物种对未来环境变化的响应均具有重要意义。塔斯马尼亚原秧鸡（Tasmanian native hen）是一种岛屿特有无飞行能力的秧鸡，同时也是某次史前灭绝事件的幸存物种。目前学界对影响该秧鸡分布的区域尺度环境特征，以及环境变化（例如气候变化）可能如何影响其未来分布的相关研究仍较为匮乏。本研究结合本地野外调查与物种分布模型（species distribution modelling），对塑造塔斯马尼亚原秧鸡当下分布格局的环境因子进行评估，并基于未来气候变化预测情景，推演其未来分布的变化情况。研究结果显示，当前塔斯马尼亚州有37.2%的区域适宜该秧鸡栖息，其适宜条件为夏季降水量较低、海拔较低、受人类活动改造的植被以及城市区域。此外，在原本不适宜栖息的区域中，城市区域可形成栖息地‘绿洲’，通过提供生存资源并缓冲环境限制因素，能够支撑具有较高繁殖活跃度的种群存续。基于气候变化预测情景，至2055年时，该秧鸡的已占据栖息范围仅会减少5%。本研究得出结论：该物种对气候变化具有较强韧性，且整体上得益于人为景观改造。综上，该物种是少数适应人类活动的无飞行能力秧鸡类群的罕见实例。