Estimating flight ranges to unravel migratory strategies: spring migration of continental Black-tailed Godwits Limosa limosa limosa

Mapping migratory routes and the distribution of species during migration requires information collected over large scales (e.g.survey data), or the ability to follow specific movements (e.g. using tracking devices), which is often limited to a few individuals. For endangered species, such techniques may be impractical, but developments in flight range modelling allow inferences about migratory routes and potential site occupancy, given a few morphological parameters. We modelled flight range in a rapidly declining population of continental Black-tailed Godwits Limosa limosa limosa departing from a staging site in Iberia during spring migration and found that the vast majority of godwits are able to reach the breeding grounds in a single flight. Contrary to the traditional use of staging sites in France (and Morocco), godwits currently staging in Iberia are predicted to fly directly to The Netherlands and be present at breeding locations earlier than previously expected and observed. Despite harbouring approximately 75% of the total population during spring migration, Iberian staging sites currently lack any legal protection. Our example of the Blacktailed Godwit illustrates the potential of this approach to identify migration strategies and locate staging sites for species of conservation concern for which such information may be virtually absent.