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Logotyp för Naturhistoriska riksmuseet
Logotyp för Naturhistoriska riksmuseet

International cooperation

Since birds do not care about national borders, international collaboration is important for studying bird migration successfully by means of ringing.


During the past decades, EURING has initiated several Europe-wide ringing projects, often designed to get results possible to use in nature protection. These projects have, for example, focussed on the migration of Acrocephalus warblers and in the late 1990s on the Swallow.

EURING also arranges technical conferences aimed to further advance the methods used for analysing recovery data.

Constant Effort Sites

The Constant Effort Sites Scheme is standardised ringing at breeding quarters during the breeding season. The aim is to ring only breeding birds and no migrants and by this the ringing has a monitoring function for the breeding bird population.

The ringing gives extensive data on:

  • population size
  • population changes
  • survival of young and adults
  • ccurrence of ectoparasites in the breeding population

Sweden has ringed birds according to the Constant Effort Sites Scheme since 1996. During the first year CES-ringing was performed at eight localities. Up to 30 localities have been involved but due to a variety of factors the participating localities were 26 in the year 2005.


At a meeting in Paris in October 1963 a union of ringing schemes in Europe was founded called EURING (European Union of Bird Ringing). The aim of the organisation was to organise and standardise scientific bird ringing in Europe.

One important issue was to produce a common code system for recoveries that, among other things, would facilitate the exchange of recovery data. EURING decided later to collect recoveries of birds ringed in Europe and store them in a database, and in 1975 the Euring Data Bank was created at the Dutch ringing centre at Arnhem.

More to read

You find more information under EURING External link, opens in new window.

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