Wintering shorebirds rely on undisturbed roost sites at high tide when intertidal feeding areas are covered. Repeated disturbance of roosts causes energy deficit and welfare harm at a critical period.
Waders disturbed from roosts expend energy on flight at precisely the moment their food source is inaccessible. The welfare cost is energy debt accumulated across multiple disturbance events in a single winter that directly affects survival and future breeding success. For already energy-stressed birds completing migrations or building reserves for the return journey, repeated roost disturbance represents a cumulative welfare harm with population-level consequences. Individual actions — keeping dogs leashed on estuary paths during winter, staying on marked paths away from roost sites — directly prevent welfare harm to individual birds. The aggregated impact of thoughtful estuary visitor behavior across multiple sites is significant.