The habitat use and foraging behaviors of waterbirds are closely related to the distribution and abundance of their food resources. Reductions in food supply can cause waterbirds to shift their habitats and adjust their foraging behaviors to meet their nutritional requirements and increase fitness. Seasonal withdraw of the water levels in the river-connected lakes in the middle and lower Yangtze River floodplain provides abundant food resources for the wintering Greater White-fronted Goose (Anser albifrons). Sedge (Carex) meadows are critical foraging habitats for herbivorous waterbirds in the hydro-fluctuation belt, which changes with hydrological conditions and climate. This study aimed to examine the behavioral responses of the Greater White-fronted Goose to temporal- spatial changes of food availability in the Sedge meadows. Fields surveys were carried out at Shengjin Lake from November 2017 to April 2018. According to the phenology of Shengjin Lake, we divided the wintering season into three periods. The food density, minimum temperature, food items, grass height, and number of foraging geese were surveyed, and samples of the foraging behavior were collected. We analyzed the relationship of the foraging behavior and habitat use relative to the food resources, using correlation and linear regression analyses. Along with the temporal-spatial variation and exploitation of food resources, the food abundance and items varied widely among the foraging sites. Over the whole wintering period, the foraging habitat with the highest utilization rate was the meadows, followed by the paddy fields, and then mudflats. Furthermore, the utilization of the meadows showed a bimodal distribution trend, while the paddy fields showed a unimodal trend, and a decreasing trend was seen in the mudflats over the whole wintering period. The results of the generalized linear model showed that the foraging rate was related to the food density and grass height, with a linearly increasing trend during the winter. With the change of food resources in the three habitats, the habitats used by the Greater White-fronted Geese shifted from meadows in the hydro-fluctuation belt to the paddy fields, and then back to the meadows. The time budget for foraging activities increased correspondingly, and there was an increase in the foraging rate to compensate for food shortages.

中文翻译：

---

升金湖越冬的大白额雁（Anser albifrons）的觅食行为：饮食变化和栖息地利用

水鸟的栖息地利用和觅食行为与其食物资源的分布和丰富程度密切相关。粮食供应的减少可能导致水鸟改变其栖息地并调整其觅食行为，以满足其营养需求并提高体质。长江中下游地区与河流相连的湖泊的季节性水位季节性回撤为越冬的大白额雁（Anser albifrons）提供了丰富的食物资源。莎草（Carex）草甸是水力波动带中草食性水鸟觅食的重要生境，水生波动性随水文条件和气候而变化。这项研究旨在研究大白额雁对塞奇草甸食物可获得性的时空变化的行为响应。2017年11月至2018年4月在盛津湖进行了实地调查。根据盛津湖的物候，我们将越冬季节分为三个时期。调查食物密度，最低温度，食物种类，草高和觅食鹅的数量，并收集觅食行为的样本。通过相关性和线性回归分析，我们分析了觅食行为和栖息地利用相对于粮食资源的关系。随着食物资源的时空变化和利用，觅食地点的食物丰度和食物种类也有很大差异。在整个冬季，利用率最高的觅食生境是草地，其次是稻田，然后是滩涂。此外，草地的利用呈现出双峰分布的趋势，而稻田则表现出单峰的趋势，并且在整个越冬期间，滩涂的土壤利用率均呈下降趋势。广义线性模型的结果表明，觅食率与食物密度和草高有关，在冬季呈线性增长趋势。随着三个生境中食物资源的变化，大白额雁所使用的生境从水力波动带的草地转移到了稻田，然后又回到了草地。觅食活动的时间预算相应增加，为了弥补粮食短缺，觅食率增加了。在整个冬季，泥滩的水量呈下降趋势。广义线性模型的结果表明，觅食率与食物密度和草高有关，在冬季呈线性增长趋势。随着三个生境中食物资源的变化，大白额雁所使用的生境从水力波动带的草地转移到了稻田，然后又回到了草地。觅食活动的时间预算相应增加，为了弥补粮食短缺，觅食率增加了。在整个冬季，泥滩的水量呈下降趋势。广义线性模型的结果表明，觅食率与食物密度和草高有关，在冬季呈线性增长趋势。随着三个生境中食物资源的变化，大白额雁所使用的生境从水力波动带的草地转移到了稻田，然后又回到了草地。觅食活动的时间预算相应增加，为了弥补粮食短缺，觅食率增加了。随着三个生境中食物资源的变化，大白额雁所使用的生境从水力波动带的草地转移到了稻田，然后又回到了草地。觅食活动的时间预算相应增加，为了弥补粮食短缺，觅食率增加了。随着三个生境中食物资源的变化，大白额雁所使用的生境从水力波动带的草地转移到了稻田，然后又回到了草地。觅食活动的时间预算相应增加，为了弥补粮食短缺，觅食率增加了。