Dunlin are the most abundant small wader on UK estuaries, using intertidal mudflats for wintering and as spring migration staging posts. Their welfare is affected by estuarine habitat loss, disturbance, and climate-linked prey changes.
Dunlin welfare during winter depends on the quality and accessibility of estuarine feeding habitats. Intertidal mudflats with abundant polychaetes and small bivalves allow birds to meet their daily energy requirements within a limited time budget; degraded estuaries with reduced invertebrate density force birds to forage longer with lower success rates. Disturbance that flushes flocks causes collective energy expenditure during high-cost flights that reduces the time available for feeding. At a population of tens of thousands on a single estuary, flock disturbance welfare costs accumulate across many individuals simultaneously. Thermal stress during cold winter conditions increases energy requirements at the same time that frozen or snow-covered high-tide roosts may displace birds from their preferred resting areas. Estuarine habitat protection through managed realignment that creates new intertidal habitat compensates for coastal squeeze and benefits dunlin alongside many other estuarine species.