Wintering area shift effects on the migration phenology of a time-limited shorebird

Many long-distance migratory birds traveling between arctic breeding grounds and tropical wintering sites are showing population declines. This is often attributed to climate change, as the advancement of arctic spring (and the related food peak) happens at a faster rate than the birds can advance their arrival in the breeding grounds, resulting in a phenological mismatch. Early arrival to the breeding grounds is thus essential for the survival of the population.

In this study, we are interested in mapping the phenology of 3 populations of bar-tailed godwits in the Wadden Sea, who all have a different combination of either African or European wintering area and Siberian or Scandinavian breeding grounds, and therefore also different migration lengths. One of these populations, the European wintering / Siberian breeding population from a normally tropical wintering subspecies is a new discovery and therefore their migration strategy and phenology are completely unknown.

Some research questions we would like to answer: What is the difference in migration phenology between the populations? Can a shift in wintering area towards the north result in changing migration phenology or strategy? How? Could this mechanism result in an escape from the increasing time limitation during stopover? Etc. We are open to suggestions from the students as well!

This project provides students with the unique opportunity to do a lot of fieldwork on the remote island of Griend, with high densities of shorebirds during the spring migration, while also getting experience working with a broad range of data types.

The project entails:

~ 2 months of fieldwork in remote areas of the Wadden Sea (mostly Griend, but also Richel and Terschelling):

• Helping with catching and tagging individuals         
• Resighting individuals, noting down fat and moult scores

Data analysis:

• Calculate time budgets and analyze space use
• Link to subspecies by available DNA data

Requirements

• Two students (at least one MSc)
• 6 months, starting February/March 2026
• Experience with fieldwork in remote areas is a pre  

Contact

If you are interested in studying birds and their migration, also in relation to climate change, and if the idea of spending 2 months in the middle of the Wadden Sea during spring migration excites you: Sign up!: anne.vorenkamp@nioz.nl.