Remote sensing and GPS tracking reveal temporal shifts in habitat use in nonbreeding Black-tailed Godwits

Knowledge of the habitat requirements for migratory species throughout
their full annual cycle is necessary for comprehensive species protection
plans. By describing seasonal shifts of space-use patterns in a key
nonbreeding area, the Senegal Delta (Mauritania, Senegal), this study
addresses a significant knowledge gap in the annual cycle of the rapidly
declining continental Black-tailed Godwit Limosa limosa. We
fitted continuous-time stochastic-process movement models with GPS
location data to describe the core areas used by 22 GPS-tagged godwits
over the 2022-2023 nonbreeding period. We mapped key habitat types, such
as floodplain wetlands and rice fields, via supervised classification of
satellite imagery. Godwits in the Senegal Delta show a distinct shift in
habitat use over the nonbreeding period. The core areas of godwits in the
early stages of the nonbreeding period (the wet season) were primarily in
natural wetlands and fields with newly planted rice. As the rice crop
matured and became too dense, godwits moved towards more recently sown
rice fields. Later, as floodwaters receded and rice fields dried out,
godwits abandoned rice fields and shifted toward natural wetlands with
fewer invasive plants, particularly within the marshes and shallow
floodplains of nature-protected areas in the lower Delta. Synthesis and
Applications: Our findings illustrate the shifting importance of natural
and agricultural wetlands for godwits at different stages of the
nonbreeding season. Protected areas in the Senegal Delta, particularly the
Djoudj National Bird Sanctuary (Senegal) and Diawling National Park
(Mauritania), are crucial habitats during the dry season as godwits
prepare for their northward migration, while rice fields take a key role
during the wet season. Conservation efforts should prioritize eradicating
invasive plants from the Djoudj and Diawling, as well as promote
agroecological management in specific rice production complexes indicated
in this study.

全面的物种保护规划，有赖于对迁徙物种完整年度周期内栖息地需求的充分认知。本研究以塞内加尔三角洲（覆盖毛里塔尼亚、塞内加尔两国）这一关键非繁殖区域为对象，描述了该区域内黑尾塍鹬空间利用模式的季节变化，以此填补了针对快速衰退的大陆种群黑尾塍鹬（Limosa limosa）年度周期研究中的重要认知空白。
本研究借助GPS定位数据构建连续时间随机过程运动模型，以此刻画2022-2023年非繁殖季期间，22只佩戴GPS追踪器的黑尾塍鹬的核心活动区域。通过对卫星影像开展监督分类，本研究绘制了洪泛平原湿地、稻田等关键栖息地类型的分布图谱。
塞内加尔三角洲的黑尾塍鹬在非繁殖季期间的栖息地利用模式呈现出显著的阶段性变化：非繁殖季初期（湿季），黑尾塍鹬的核心活动区域主要集中在天然湿地以及新插秧的稻田中；随着水稻成熟、田间郁闭度过高，黑尾塍鹬会转移至新近播种的稻田区域；后续随着洪水退去、稻田干涸，黑尾塍鹬会放弃稻田，转向入侵植物更少的天然湿地，尤其是三角洲下游自然保护区域内的沼泽与浅滩洪泛平原。
研究总结与应用展望：本研究结果揭示了在非繁殖季的不同阶段，天然湿地与农业湿地对黑尾塍鹬的重要性动态变化。塞内加尔三角洲的自然保护区域，尤其是朱贾国家鸟类保护区（Djoudj National Bird Sanctuary）与迪亚韦林国家公园（Diawling National Park），在旱季黑尾塍鹬筹备北迁时，是其关键栖息地；而湿季的稻田则发挥核心支持作用。相关保护工作应优先开展朱贾与迪亚韦林区域的入侵植物清除工作，并针对本研究划定的特定稻田生产区，推广农业生态化管理模式。