Burrow ambient temperature influences Helice crab activity and availability for migratory Red-crowned Cranes Grus japonensis

For migratory birds that specialize on particular benthic macroinvertebrate species, the timing of migration is critical since prey availability may be temporally limited and a function of local ambient temperature. Hence, variation in local ambient temperature can influence the diet composition of migrant birds, and consequently they may be constrained by which stopover and wintering sites they are able to utilize during periods of colder temperatures. Here we use faecal analysis, observer-based population counts, digital video-recordings, and temperature data to test five predictions regarding the influence of local ambient temperature on the activity and availability of mudflat crabs - a key prey resource at three staging/wintering sites in eastern China, for migratory Red-crowned cranes (Grus japonensis) and how this subsequently influences crane diet and use of wetland sites. Pearson’s correlations and generalised linear models revealed that mudflat crabs became significantly more ...

针对专食特定底栖大型无脊椎动物（benthic macroinvertebrate）的迁徙鸟类而言，迁徙时机至关重要，因猎物可获得性兼具时间限制性且受当地环境温度调控。据此，当地环境温度的变化可影响迁徙鸟类的饮食组成，进而使其在低温时段可利用的停歇与越冬场所选择受到限制。本研究采用粪便分析、基于观测者的种群计数、数字视频录制及温度数据，针对迁徙丹顶鹤（Grus japonensis）检验5项预测：其一，当地环境温度如何影响作为中国东部3处停歇/越冬地关键猎物资源的滩涂蟹（mudflat crabs）的活动与可获得性；其二，该温度调控效应后续如何影响丹顶鹤的饮食组成及湿地场所利用。皮尔逊相关分析（Pearson’s correlations）与广义线性模型（generalised linear models）结果显示，滩涂蟹的……显著增强。