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.

Colour-ringing

Information has now been received about two of the colour-ringed birds that we reported recently.

The Black-tailed Godwit seen in Tavira on Boxing Day 2008 was a male ringed as an adult in SW Iceland in April 2002. It was seen in the Netherlands and France in 2003 and there were more sightings in France in 2003, 2004 and 2005. However, it has clearly taken a liking to Tavira as this is its third consecutive winter on the saltpans on the edge of town.

The Eurasian Spoonbill that we reported from SW Spain in January was ringed as a nestling in the Netherlands in July 1994. There have been numerous sightings since then, mainly in France but it was seen in the Huelva area as long ago as 1996 and has been reported as a winter visitor there in 2003/04, 2004/05 and 2005/06.

Back on the local patch

With the forecast for the weekend and beyond including the possibility of rain, we decided to take advantage of today’s glorious weather and have a walk from Tavira, around the saltpans towards Santa Luzia. It’s a walk we do fairly regularly and amongst the 60 or so species recorded in an almost entirely wetland area there were few surprises. An exception was a Common Quail that we flushed from the vegetation at the edge of one of the pans. It flew up from almost under our feet and we had really a good view of it in flight. It may seem an unlikely place in which to see a Quail but it is not the first time we have come across them in this habitat.

Notable among 20 species of shorebirds were 109 Knot roosting on the saltpans at high tide and a colour-ringed Black-tailed Godwit, details of which we have reported. An Osprey, in the middle of a dry pan eating a fish, was in exactly the same place that we saw it on 26th November and 14th December. Birds really are creatures of habit!

Santa Luzia saltpans

Most of the ducks that were here last month now seem to have moved on leaving just 30 or so Teal and a couple of Shoveler. Numbers of Greater Flamingos and Spoonbills are also much reduced now; just 35 Flamingos today and even fewer Spoonbills.

We found just a single Audouin’s Gull and a handful of Mediterranean Gulls among the many Lesser Black-backs and Black-headeds; the Caspian Tern that flew over was probably the same bird we saw in Tavira yesterday. Our walk was enlivened by frequent sightings of Kingfishers. It’s difficult to say how many individuals were involved but probably half a dozen at least and always nice to see.

Finally, the predicted maximum temperature today (www.google.co.uk) was 16° C but by 2.00pm it was several degrees warmer; both Clouded Yellows and Wall Browns were flying. Not bad for Boxing Day!

Colour-ringing

Colour-ringing is a valuable research technique that enables studies to be made that would be impossible using just the usual numbered metal ring. The main and obvious advantage is that a colour-ringed bird can be identified as an individual without the need for it to be re-captured and the ring number read. It follows from this that repeated sightings of a bird will yield much more information than could ever be hoped for from conventional ringing. Some colour-ringing projects involve behavioural research in a restricted area such as detailing the day-to-day activities of particular birds, while others are concerned mainly with movements between areas and following and discovering the timing of seasonal migrations. The website http://www.cr-birding.be/ maintained by Dirk Raes has details of all the European colour-ringing projects and this is our prime source of information.

There are lots of colour-ringed birds here on the Algarve. Over the last few years we’ve seen lots of Greater Flamingos and Spoonbills, several Slender-billed Gulls and Audouin’s Gulls, a Black-tailed Godwit and at least one Black-winged Stilt. More often than not the Flamingos, Spoonbills and gulls are too far away for us to read the rings, while Black-tailed Godwits in particular are nearly always in such deep water that we can’t see whether they have rings or not. Sometimes it requires a lot of time and patience to get the ring details and be sure that it has been read accurately. To be honest, we have to be in the right mood but when we do get ring details and send off a report we are always interested in the response we receive - if we get one! Dirk Raes warns that while some colour-ringing schemes provide swift replies, others don’t reply at all, which we find both surprising and disappointing. It is the feedback we receive that is our motivation for reading and reporting colour rings. We are never going to be in the mood to read rings on some species because we know that we ourselves will never learn anything as a result of reporting them.

Colour-ringed Spoonbill

Recently (27th November) we saw a colour-ringed Spoonbill at Alvor and sent the details to Otto Overdijk in The Netherlands. We had a reply almost immediately. The bird, probably a male, had been ringed as a nestling on 29th May this year in Schleswig-Holstein, Germany. It was later seen in Denmark (August) and was reported from Lagoa dos Salgados here in the Algarve on 8th October. Thank you Otto for sharing these details and for replying so quickly.