Tuesday 9 July 2013

Colour-rings

Something we very soon noticed when we started birding in the Algarve was the relatively high number of birds that were colour-ringed.  Whereas in the UK we had been used to seeing a few Mute Swans and Canada Geese sporting Darvic (PVC) rings or perhaps an occasional gull or wader, in the Ria Formosa and at Castro Marim we were seeing colour-ringed birds almost every time we went out.

By colour-rings we mean multiple rings (or flags) with a unique combination of colours or single rings that are big enough so that it is possible with the aid of a telescope to read an inscription on them.  We also sometimes see nasal saddles fitted to ducks and neck collars on Red-knobbed Coots and while these are obviously not rings as such, they do serve the same purpose, which is to identify a bird as an individual.

Greater Flamingo - from Italy

Because of their size, colour-rings are most suitable for use on long-legged birds and the first ones we saw in the Algarve were on Greater Flamingos.  It’s not unusual to see up to 1,000 or even 2,000 Greater Flamingos at Castro Marim so there is plenty of scope for reading rings if we have the time and can get close enough to the birds!  We soon found that, as well as Flamingos, quite a high percentage of Spoonbills were also colour-ringed and that several species of gulls, particularly Audouin’s Gulls, were also ringed.  We have now sent reports relating to 18 different species and these have originated from more than a dozen countries.

Spoonbill - from The Netherlands

Looking for colour-rings, reading them and reporting them have all become part of our birding routine.  In 2012, we reported more than 200 ring details.  Receiving details of the life-histories of individual birds has added greatly to our knowledge of the origins, the movements and the ages/life expectancies of the birds involved and still we get surprises like the Italian-ringed Oystercatcher that we found in Tavira.  We have also been able to recognise birds that return to the Algarve year after year such as Common Redshank H19 that we have blogged about previously here.

  Common Redshank - from The Netherlands

Oystercatcher - from Italy

However, it might all have been very different!  We might easily have been put off the whole idea of reading rings.  Probably our expectations were unrealistic but when we began sending off reports of ring details we thought, rather naively as it turned out, that we might receive a reply within maybe a week or two.  Instead, the reality was that months went by with no word from anybody and we started to think we were wasting our time.  Perhaps there was no longer any interest in the rings we had reported; maybe the ringer had died!  It would have been easy to reach the conclusion that reading and reporting rings wasn’t worth the effort.  And sometimes it can be quite an effort when we have to wait long periods for birds to come closer or to move out of the deep water that is covering their rings.

Slender-billed Gull - from Spain

We now know that response times vary greatly and we try not to be too impatient.  We know, for instance, that if we report a Dutch-ringed Spoonbill or a Mediterranean Gull ringed in Belgium or France, we can be reasonably sure of a reply by return, maybe even the same day!  On the other hand, we also know that it might be six months or longer before we get a response about some other species and from some other countries.  In the past few days we have received details of six birds that we reported last December and we have others outstanding that go back further than that.

Mediterranean Gull - from The Netherlands

Last year we joined the Yahoo! Group, c-r birding, which has about 600 members who communicate with each other on various aspects of colour-ringing.  It was interesting that the very first contribution we read there was from someone complaining about the length of time he was waiting to hear about a Black-headed Gull ring he had reported.  Maybe that person's expectations were also unrealistic, but were they unreasonable?  Prompt replies would not only be courteous but would surely also encourage further reports.

How do we find out where to send details of the rings we read?  Well, in theory, details of all the colour-ringing projects in Europe can be found at www.cr-birding.org or failing that www.cr-birding.be (this website is slowly being phased out).  It is also possible to report ring details by filling out a form on the Euring website but the advice there is to look first at www.cr-birding.org.  Occasionally we do find birds that have rings which we can’t match up with one of the listed projects and so it would seem do quite a few other people as queries about such rings appear very regularly in the Yahoo! Group emails.  Why, we have to wonder, would anyone who is colour-ringing birds in Europe and presumably wanting people to report them, not make sure that details of their project are on the relevant website?  It takes some understanding!

Glossy Ibis - from Spain

All ringing is, of course, licensed and, thankfully, beyond that there is also some regulation of the growing number of colour-ringing projects in Europe with the aim of avoiding the chaos that would result from duplication of colour combinations or codes.

Some of the difficulties arising from ring reports inevitably result from rings being misread.  When looking at a small ring from a distance it is easy to confuse a 2 with a Z or a 5 with an S.  Clearly it would be best when setting up a new project to avoid such possibilities occurring.  Another problem is that the colour of some rings can fade or even change over a period of years, particularly if they are under water for much of the time.
  
Audouin's Gull - ringed in the Ria Formosa

Replies from some of the ringing projects include not just details of the individual bird that we have reported but also information about the project itself, its aims and objectives and sometimes even links to results achieved so far.  We would welcome much more of that sort of feedback.  We have to assume that birds are being ringed for a particular purpose but it is always nice to have some details.

Reporting colour-rings certainly involves a few difficulties and frustrations but it adds greatly to our enjoyment of birding in the Algarve.  Already we are looking forward to the autumn and winter and the return of all those colour-ringed birds.

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