Human disturbance and shelter-seeking mechanisms of wintering Red-crowned Cranes (Grus japonensis) in a farmland-wetland ecotone outside a national nature reserve, Fangqiang Farm, Yancheng, China

Natural wetland loss forces endangered Red-crowned Cranes (Grus japonensis) to use human-modified farmland-wetland ecotones outside formal protected areas. Fangqiang Farm in Yancheng, China, is a critical unprotected wintering site hosting dozens of cranes annually. From winter 2023/2024 to 2024/2025, we quantified human disturbance regimes and shelter-seeking mechanisms of wintering cranes using line-transect sampling, instantaneous scan-sampling, opportunistic long-range telephoto photography, semi-structured interviews, field-recorded distance classes, Fisher’s exact tests and logistic generalized linear models. The complete dataset contained 61 crane occurrence records, all of which had an identified habitat type, and 61 disturbance events with measured distances. Habitat use was dominated by winter wheat fields and dry reed marshes, while riverine wetlands and unseeded fallow farmland were less frequently recorded. Dry reed marshes were used mainly for resting. Response rate remained high across distance classes, whereas escape rate was highest at short-to-intermediate distances and declined markedly beyond 500 m. Agricultural machinery showed the highest escape rate, followed by motor vehicles and resident daily activity. When disturbed, cranes adopted four recorded shelter strategies: behavioural adjustment within the original patch, retreat to riverine wetland, retreat to dry reed marsh and long-distance flight out of the local patch. Farmland-wetland mosaics outside nature reserves can sustain wintering crane aggregations, but cranes rely on remnant reed patches as behavioural refugia. We propose differentiated zoning management, farm operation time-shift schemes and retention of reed shelter patches to reconcile agricultural production with crane conservation in unprotected ecotones.