There are several projects monitoring the health and life cycle of Mute Swans on the Thames. You can take part in these projects by walking a section of the river and reporting any birds you see with a colour-ring. You’ll learn when the swan was ringed, how old it is, and about the history of any other sightings.
You’ll need to note a few details for each bird you see. The simple stuff is the date and time you saw the bird, plus the stretch of the Thames.
The ringy bit is a little more involved but fun to learn about.
For each bird, note:
- the colour of the colour-ring
- the colour of the text on the colour-ring
- is the colour-ring on the bird’s left or right leg?
- are there any metal rings? Which leg are they on?
Let’s look at an example bird. This swan’s rings can clearly be seen as it dunks to feed…

A white colour-ring can clearly be seen on the left leg with a black sequence of letters and numbers. For this swan your report would look like this:

It looks like gobbledygook at first sight, but once you’ve used it a few times it becomes second nature, and MUTE SWAN WN(T31)/M reads almost like a shorthand.
Starting with the left leg, note the colours of the ring with the sequence bracketed. The tricky things are to find the letter colour codes and remembering to state the ring colour before the sequence colour. Any rings on the right leg are noted after a “/”.
Colour | Code |
Black {Nijer} | N |
Blue, Dark | B |
Blue, Pale | P |
Brown {Umber} | U |
Metal Ring | M |
Dark Pink {Carmine} | C |
Green, Dark | G |
Grey {Silver} | S |
Light Green {Lime} | L |
Orange | O |
Other metal ring | A |
Pink, Light | K |
Purple {Violet} | V |
Red | R |
Turquoise | Q |
White | W |
Yellow | Y |
That’s a lot of colours but thankfully only two ring colours seem to be popular for Thames’ swans. These are White and Orange. Both have black text and black is coded N (because B is the code for Dark Blue).
If you’d like to take part or find out more, drop me a line, Carl Hunter-Roach, at middlethames@hunterroach.com
And what of our swan, WN(T31)/M? Well, she’s a girl, tagged back in July 2005 at Hurley, making her 15 years-old. She was next seen in 2015 at Windsor Marina with five cygnets and then not again until she turned up on my stretch of the Thames at Windsor this November.