Application of new technologies to the study of Eurasian Woodcock migration.

Abstract

The last five years have seen a huge expansion in studies of bird movements and migration owing to rapid technological developments in techniques which provide alternatives to ringing. We give an overview of stable isotope analysis and various options for tracking migration routes of individual birds. We demonstrate that stable hydrogen isotope analysis of feathers sampled on the wintering grounds is a valid technique for assessing Eurasian Woodcock breeding origins and population composition at different sites. We present preliminary data from geolocators indicating that Woodcock undertake their migrations by making flights of 590-1,040 km interspersed with stops of 8-16 days. Flight speeds average c.30 km/h, but may reach 93 km/h. We discuss the relative merits and application of geolocators, archival GPS tags and satellite tags to the study of Woodcock migration.