Key aspects of the migration ecology of Icelandic Black-tailed Godwits

Icelandic Godwits provide an excellent system in which to study migration strategies and their consequences for population dynamics, for several reasons:

  I. Relatively limited global distribution

As Icelandic Godwits breed almost exclusively in Iceland, the entire population can be relatively easily surveyed, especially during the spring arrival period when many birds occur on a small number of stop-over sites in Iceland before moving to their territories.
Icelandic Godwits are also quite unusual in that different breeding populations have very little overlap in winter. The Icelandic and nominate subspecies overlap in Iberia in winter but most Icelandic Godwits winter further north where they are the only black-tailed godwits present.

Icelandic Godwits in southern Iceland upon arraval in April 2008

  II. Observability

 The coastal areas used by Icelandic Godwits also attract many bird-watchers and godwitologists who observe and report marked Godwits. The involvement of these observers is fundamental to the research and it is their contribution that also drives the project forward.

  III. Attractiveness

  As Icelandic Godwits are gregarious, conspicuous and very beautiful, they attract people’s attention, which helps to generate high reporting rates of colour-ringed birds. The great majority of birds have been resighted and many have been seen hundreds of times. Thanks to the work of keen “godwitologists” the life story of these amazing birds is very colourful, not to mention the stunning colours on the legs...

  IV. Current population status

 Many migratory bird species are currently declining in numbers and range, probably as a result of interactions between habitat loss and climatic changes. Understanding and addressing the causes of these declines is complex because of the need to understand the links between processes in breeding and wintering locations often thousands of kilometres apart. In declining species, range contractions often mean that birds are no longer present in the areas where the problems occur, and so the cause of the decline can be obscured. Icelandic Godwits are quite unusual in that they have been increasing in number and range for several decades. This provides a rare opportunity to explore how survival and breeding success change as population size and range changes.