In the Netherlands Mute swans are color ringed with a coded white leg ring or a yellow collar. Swans with a yellow collar also receive a yellow leg ring with the same code. The collar code consists of two letters and two numbers (eg PN37 or P12A). For Dutch yellow collars, the first character is always a P. Enter the species [Mute Swan], the type of marking [neckband yellow] and the code on the collar. The yellow leg ring does not have to be entered separately.

A Dutch leg ring code consists of a letter followed by three numbers. Mute swans with a white leg ring can be reported by entering the species [Mute swan], the type type marking [legrings (coloured)] and the code on the leg ring. Note: enter the letter W for the code on the ring to indicate that it is a white ring. So a swan with white ring A123 has the code WA123 (without space or hyphen).

The letter in the first position indicates which project the bird belongs to and where the bird is ringed. Mute swans with ring codes that start with an A, C, E or H come from Groningen. Codes that start with a Y come from Utrecht.

Groningen

The ringing program for Mute Swans in Groningen started in the harsh winter of 1979. Breeding birds and their young, but also moulting swans, are caught and ringed during the summer, in addition, a number of birds were caught during migration or in winter. In 1989, cygnets were ringed with yellow collars with black inscriptions for the first time. Since 2016, in addition to yellow collars, birds are also ringed with white leg rings.

The ringing program is part of the long-term population study of the Swan Working Group Avifauna Groningen. One of the most important research questions concerns the dispersion and survival of Groningen Mute Swans. The researchers look forward to all observations with interest. These provide valuable information on movements, demographic parameters and ecology. With this knowledge Mute Swans can be better protected.

Mute swans can also be ringed with just a steel ring. We also look forward to readings and finds from these birds. Preferably report these to your ringing centre (outside the Netherlands) or enter them in www.griel.nl (sightings in the Netherlands).

If you have any questions or comments regarding the Mute Swan ring project in Groningen, please contact Jeroen Nienhuis.

Utrecht

The ringing program for Mute Swans in Utrecht started in 2018. Most birds are caught in summer. Except breeding birds and their young, we also catch moulting swans. Some birds are caught in winter. In addition to a metal ring, the swans are also provided with a white leg ring with black inscription. Rings that start with Y0 are ringed as an adult bird. If the ring starts with Y1 or Y2, the bird is usually ringed as cygnet.

The ring program is part of a population study by VRS De Haar in Vleuten. The research area includes the province of Utrecht, with extra attention for the areas of Utrecht-West, Vleuten, Haarzuilens and Kockengen. Swan drifters have been active in this area in the past. The main research questions concern the differences between the “truly wild” Mute Swans and the birds that come from the kept populations and the dispersion and survival of the Mute Swans in this area.

The researchers look forward to all observations with interest. These provide valuable information about the movements, demographic parameters and ecology of the Mute Swan.

If you have any questions or comments regarding the Mute Swan ring project in Vleuten e.o. please contact VRS De Haar.

Other projects

There are also other Mute Swan projects outside the Netherlands that use color rings (collars and leg rings), see www.cr-birding.org.