Birds in milder western European countries and on Atlantic islands are resident. The populations breeding in north-west and southern Europe are mostly sedentary. The birds' spring migration commences in February; breeding territories are reached between March and May. Spring migration movements of woodcock are influenced by weather conditions, however this does not have a major effect on their subsequent breeding success. The Eurasian woodcock has a large range, with an estimated Global Extent of Occurrence of 10 million square kilometres and a population of an estimated 15 million to 16 million birds. Because of its large range, stable population trend and large population size, the species has been evaluated as Least Concern. The most important threat to the population of the Eurasian woodcock in the breeding range is the increased fragmentation of its woodland habitat. At other times of year, a reduction in the amount of permanent grassland and an increase in the intensification of farming are also threats, and the species' susceptibility to avian influenza may have an impact in future. The Eurasian woodcock's required breeding habitat is large, unfragmented areas of broadleaved deciduous or mixed broadleaved and coniferous forest, with dense undergrowth of plants such as brambles, holly, hazel, gorse, bracken, or bilberry. On a small scale, Eurasian woodcock appear to prefer woods containing birch and were less likely to be found in beech dominated woods. They also prefer woods further away from urban areas. Breeding territories must include a mix of dry, warm resting places, damp areas for feeding, and clearings for flight. In larger woods, wide "rides" (open tracks through the wood) and small clearings are important. In winter, Eurasian woodcock also use scrubland during the day but in freezing weather they may use intertidal mud. Behaviour Eurasian woodcock are crepuscular (most active at dawn and dusk) and rarely active during the day unless flushed, when they fly off with a whirring wing noise. The flight is somewhat owl- or bat-like; woodcock fly fast and directly while migrating or crossing open country, but fly erratically with twisting and fluttering once in woodland. They are usually solitary and migrate singly, but may congregate when weather or geographical conditions force them to do so. This species is parasitised by the moorhen flea, Dasypsyllus gallinulae. Breeding The male performs a courtship display flight called 'roding' at dusk between April and June. A mating call is performed during courtship display