Bureau Waardenburg
Varkensmarkt 9
4101 CK Culemborg
the Netherlands
T: +31 (0) 345 512710
email buwa

Grote sterns uit de Delta
Your location:

Sandwich Terns from the Dutch Delta

Sandwich terns are one of the iconic breeding birds of the Dutch coastal zone. The largest numbers are present roughly between April and September, although a small number winter in the Netherlands.

Additionally, large numbers of Sandwich terns from other European colonies also use Dutch waters during migration. In this period, Sandwich terns can also be found far offshore. Since the last major population crash in the 1960s numbers have increased steadily in the Netherlands, and currently numbers are stable; although still only half that of between 1930 and 1960.


Since 2010, a small group of volunteers (the Delta Ring group) have colour-ringed nearly 3000 juvenile and adult Sandwich terns in three colonies in the Dutch Delta. The majority of these people are working for Bureau Waardenburg (Culemborg), the Research Institute for Nature and Forest (Brussel) or Delta Project Management (Vlissingen). The main aim of this project is to study dispersion and prospecting behaviour as well as site fidelity and survival. Secondary aims are to collect information on migration ecology, stop-over and wintering areas.

Over the years we collected many sightings from northern Scotland to the Eastern Cape, South Africa, as well as from the Mediterranean, but we hope to collect many more sightings. We hope that you too will check the legs of every Sandwich tern you encounter and submit any sightings to us! All of our rings have a 3-digit alpha-numeric code (or 3 digits and a '.' (point)) and are either blue, white, yellow or lime, starting with either 'N', 'H' or '2'. More infomation can be obtained by contacting Ruben Fijn: