Data from: Non‐breeding areas and timing of migration in relation to weather of Scottish‐breeding common sandpipers Actitis hypoleucos

The number of breeding common sandpipers has declined in Britain due to poorer return rates from non‐breeding areas. To investigate little known aspects of their annual cycle, breeding common sandpipers were fitted with geolocators to track their migrations and determine their non‐breeding areas. Ten tagged birds left Scotland on 9 July (median dates and durations are given throughout the abstract). Short‐term staging was carried out by some birds in England and Ireland, then for longer by most birds in Iberia before continuing to West Africa, arriving on 28 July. Six birds spent most of the non‐breeding season (October–February) on the coast of Guinea‐Bissau, suggesting that this is a key area. Single birds occurred in Sierra Leone, Guinea, the Canary Islands and Western Sahara. The southward migration from Scotland took 17.5 days (range 1.5‐24 days), excluding the initial fuelling period. The first northward movement from Africa was on 12 April. Staging occurred in either Morocco, Iberia or France. Arrival in Scotland was on 2 May. The northward migration took 16 days (range 13.5‐20.5 days). The main migration strategy involved short‐ and medium‐range flights, using tail‐winds in most cases. Variation in strategy was associated with departure date; birds that left later staged for shorter durations. Coastal West Africa provides two major habitats for common sandpipers: mudflats associated with mangroves and rice fields. Although the area of mangrove has been depleted, the scale of loss has probably been insufficient to account for the decline in sandpiper numbers. Rice fields are expanding, providing feeding areas for water‐birds. Meteorological data during the migrations suggest that the weather during the southward migration is unlikely to contribute to a population decline but strong cross‐winds or head‐winds during the northward migration to the breeding grounds may do so.

繁殖期普通鹬（common sandpiper）的数量在英国有所下降，原因是其从非繁殖区返回的比率降低。为探究其年度周期中鲜为人知的方面，研究人员为繁殖期普通鹬配备了地理定位器（geolocator），以追踪其迁徙路径并确定其非繁殖区位置。10只被标记的个体于7月9日离开苏格兰（摘要中所有日期及持续时间均为中位数）。部分个体在英格兰和爱尔兰进行短期停留，随后大多数个体在伊比利亚半岛停留更长时间，之后继续前往西非，于7月28日抵达。6只个体的大部分非繁殖季（10月至次年2月）在几内亚比绍海岸度过，表明该区域是关键栖息地。另有单一个体分别出现在塞拉利昂、几内亚、加那利群岛及西撒哈拉。从苏格兰出发的南下迁徙耗时17.5天（范围1.5-24天），不包括初始的能量补充期。首次从非洲北迁的时间为4月12日。中途停留地包括摩洛哥、伊比利亚半岛或法国。抵达苏格兰的时间为5月2日。北迁耗时16天（范围13.5-20.5天）。其主要迁徙策略为中短途飞行，多数情况下借助尾风。策略的差异与出发日期相关：较晚出发的个体停留时间更短。西非沿海为普通鹬提供了两类主要栖息地：与红树林相关的泥滩及稻田。尽管红树林面积有所减少，但损失规模可能不足以解释普通鹬数量的下降。稻田面积正在扩大，为水鸟提供了觅食区域。迁徙期间的气象数据表明，南下迁徙期间的天气不太可能导致种群数量下降，但向北迁徙至繁殖地途中遭遇的强侧风或逆风则可能造成这一结果。