Reporting Sanderling colour ring combinations

Sanderlings are tagged with coloured rings on their legs that make them individually recognisable in the field. Observations of those marked birds yield information about:

• Migration routes and timing of migration
• Size of the flyway population
• Survival probabilities
• Home ranges: the size of the area that sanderlings use

More general information about colour-ringing of waders can be found here and more background information about the project here.

Which rings are used and how do I write them down?

The following notes on coding flag combinations relate only to Sanderlings.

Sanderlings are provided with a metal ring on the left or right tibia (above the "knee") but the location does not need to be noted to identify a Sanderling individuals. More important is that each bird also receives two colour-rings on each tarsus (below the "knee"), thus four colour-rings in total, plus an extended ring, or "flag". The position of the flag (on the left or right leg, above, below or between the two other colour-rings on the leg) is crucial. In combination, the colour and position of the flag tells us where each bird has been ringed. Colours used for both rings and flag are: YELLOW, WHITE, RED and GREEN (plus BLUE will be used in the near future). Examples can be seen in the panel on the right.

On the life history sheets you will find a code with letters and a number, such as this: G5YRWG. The first letter stands for the colour (Green =G) and the number for the position of the flag, where:

1. on the left tibia (above the "knee")
2. on the right tibia (above the "knee")
3. on the left tarsus (below the "knee") above both rings
4. on the right tarsus (below the "knee") above both rings
5. on the left tarsus between both rings
6. on the right tarsus between both rings
7. on the left tarsus below both rings
8. on the right tarsus below both rings

Note that positions 1 and 2 are not used for this project. The letters following the number stand for the colours of the rings (Y= Yellow, R = Red, W = White and G = Green) read downwards on the left leg first followed by the right leg. So G5YRWG has a yellow ring above a red ring on the left tarsus with a green flag between the two rings. On the right tarsus it has a white above green ring.

What do I need to report?

When you have observed a colour-ringed sanderling, you can report it to find out where the bird has been ringed and what its movements have been since (see: Where do I report colour-ringed sanderlings?). You need to report the following:

• Date of observation(s)
• Location
• Your name and that of any possible other observer(s)
• The observed colour-ring combination (see: Which rings are used?)

It is also very much appreciated if you report:

• Time (approximate) of observation(s)
• Number of sanderlings that you have checked for colour-rings
• Total number of sanderlings in the area
• The behaviour of the bird
• Coordinates of the location (in degrees, for example: 42°13’N 08°15’W)
• The age of the bird (only well possible between July until mid October)
• The plumage (winter plumage, in transition or full breeding plumage)
• Pictures of the colour-ringed birds are always welcome
• Any remarks (did the bird look healthy, what was it feeding on, etc)

Also see: Anyone can help!

Where do I report colour-ringed sanderlings?

Reports of sanderlings with colour-rings are highly appreciated! We are working on a form on this website for easy reporting of your observations. Until this is available, you can report your observations to the project leader, preferably by e-mail:
Jeroen Reneerkens
Animal Ecology Group Centre for Ecological and Evolutionary Studies
University of Groningen
Po Box 14 9750 AA Haren The Netherlands
E-mail: J.W.H.Reneerkens@rug.nl

In return you will receive information about the date and location of colour-ringing, as well as of previous observations. When you have observed a bird that was ringed in Greenland, you will also get a report about its family life.

Avoid mistakes in ring reading!

For the research it is crucial to be able to trust the reported observations of colour-ringed sanderlings. We prefer to receive a few reliable observations rather than many of which some are not correct! Sanderlings run fast, the best way to read colour-rings is by following the birds with your telescope until it stands still. That is the (often short) moment when you can see which rings are left and right and up and down. Only write down the codes in your notebook when you are absolutely sure. If you are not 100% sure, please let us know when you report your observation. We know that it can be difficult to read colour-rings of sanderlings, and are unable to read the combination ourselves too, sometimes.

The most common mistake in ring reading is the confusion of the left and right leg. Left and right are the bird’s left and right leg, so when you look at the birds’ breast, the right leg is left and the left leg is right!

Another common mistake is that two colour rings of the same colour are reported as one. Please realise that there should always be four colour-rings and a flag, and that some birds have been ringed with four rings and a flag all being of the same colour.

Please note that a very few sanderlings already had a metal ring on the tarsus when we recaptured them. In those cases the metal ring is on the tarsus with two colour rings, but never together with a flag.

How many sanderlings have been colour-ringed and where?

Our colour-ringing project is ongoing, which means that the number of birds with colour-rings increases each month, and so does the number of observations.

At 15 March 2009 the list was as follows:
In total 1949 sanderlings have been colour-ringed of which 1405 (72%) has been resighted in the field at least once. In 2009 sanderlings will also be colour-ringed in Svalbard, Scotland, France, Russia and Kenya.

Why do you use so many rings and does it harm the birds?

Colour-rings are conspicuous and not particularly beautiful, so if the number of them on each bird can be limited, it should be done. However, for our research questions to be answered, we need to colour-ring many birds that are individually recognisable. In the vast majority of areas less than 1 % of the sanderlings is colour-ringed, but those provide us with information that can be (and has been!) used for the conservation of sanderlings and other wader species and their habitats. By using four rings and a flag we can ring 1,536 different individuals per flag colour. Birds with and without colour-rings have equal survival probabilities. This has been thoroughly investigated in several studies, and is very important because with our study we use colour-rings to measure survival, not to influence it.

Other colour-ring projects

In Europe, Africa and Asia this is the only project that uses flags (extended colour-rings) on sanderlings. There are also other colour-ring projects on sanderlings. Observations of birds ringed for those projects should be reported to the responsible coordinators. You can find them on this website: www.cr-birding.be

In case of doubt we can always help to find out to whom a colour-ringed sanderlings should be reported.

Please note also that we know of a few cases where birds colour-ringed by us have lost a flag! We know the identity of those birds and are eager to hear of observations of them.

Sanderling:

• Introduction
• What are they
• Background
• How to help
• Report resightings
• Colour-marking
• Sanderling links

Images of colour marked Sanderling

Code=W3YWRY

Code=G5WYGY

Code=G5YRYR