Wintering behaviour and spatial ecology of Eurasian Woodcock Scolopax rusticola in western France

摘要

The spatial ecology of wintering Eurasian Woodcocks Scolopax rusticola was investigated to determine whether hunting-free forest reserves offer adequate protection to all individuals. The analysis of movements performed by 65 radiotagged Woodcocks during three consecutive winters in Brittany revealed the existence of three types of individual strategies. During daylight hours, 34% of birds remained in a unique core area (of 1.1 ha) during January and February while 18% used several core areas successively (never came back to a previously used core) and 48% alternated between several core areas (exploratory movements around several core areas visited several times). Alternating diurnal strategies seemed to result from a lower abundance of food (earthworms), whereas this was not the case in the unique core-use strategy. The successive core-use strategy was considered as a subset of the 'unique' strategy, for which birds were forced to change sites because of a lower abundance of food after depletion. During the night, 62% of birds showed alternative core-use whereas 33% lived in a unique core and the 'successive' strategy was almost absent. As food abundance was similar in the night cores used by birds under each strategy, we discuss the reasons for the nocturnal strategies in relation to individual differences in territoriality or the ability to detect predators. Both diurnal and nocturnal strategies led most of the birds to leave the reserve, and the important use of bocage and hedges by day (by 39% of birds) and meadows at night (83% of birds used meadows on more than 70% of nights), around the protected forest, call for their inclusion in management plans around reserves.