An intriguing Redwing recovery

 

A Story about Redwing RZ26165

Back in October 2016, BSM 8040 Partership group members put in a lot of effort to ring 602 Redwings which were gathering in big numbers on Cannock Chase. This site is now run by the West Midlands Ringing Group and the ringer of the actual bird described below is now a member of that group.

One of these Redwings (bearing ring number RZ26165) has been reported from a rather exciting place. The map shows the original ringing site on Cannock Chase on 20^th October 2016, and the finding site which is in Ashinsky District, Chelyabinsk Oblast, Russia some 3896 kilometres away!! This is one of the most easterly recoveries on record and as such is pretty significant in itself. Only the leg of the bird with the ring on it was found and no details were provided by the finder about how long the bird had been dead prior to the ring being found on 15^th July 2019.

 We have not linked the two sites by a line as is often shown on these repots, because this implies that the bird flew from one site directly to the other; and we are pretty sure that it didn’t do that. So here we have the essence of the fascinating back-story and the puzzle of unravelling it which illustrates beautifully the strengths and weaknesses of the ringing process. On the one hand, if birds like this had not been ringed we would have had no idea of the range and scale of movements undertaken by Redwings. This is one of the major strengths of the current scheme. On the other hand, however we are left guessing about what movements the bird carried out between ringing and finding. Although this is a shortcoming, the fact that over the years we have built up a picture based on lots of other similar recoveries is a strength. Fortunately we can speculate on the movements of RZ26165 based on this large number of recoveries.

The map shows the breeding area of Redwings in northern European taiga forests. It’s pretty certain that our bird was hatched somewhere in this area in summer 2016 because it was aged as a juvenile when ringed. It then moved out during early autumn along with millions of others and found its way to Cannock Chase where we ringed it. Now we get to the speculative phase of the story. The bird will either have stayed somewhere in the UK during the winter—or perhaps carried on south into France or Spain. During late Spring 2017 it will probably have flown back to northern Europe—maybe to its natal area where it most probably will have bred. We have no idea where it went during the winter of 2017/18.

The data bank of Redwing recoveries suggests that individuals can vary the direction and destiny of their winter quarters year on year. So we speculate that our bird set off after breeding from northern Europe again in autumn 2018, but this time it set off in a south easterly direction. We speculate that it spent the winter in south eastern Russia but before it could migrate back to its breeding grounds in spring 2019 it met its end—probably being killed by a predator. Later in that year, July in fact, the leg and ring were found and details sent to the BTO.

Quite how true this story is, is debateable, but it is based on the evidence we have in the system. But in truth we will never know about this particular bird’s movements. In fact we will not know these details for sure until we are able to fit satellite trackers to small birds. This will happen in the near future we believe and then we will get some incredibly detailed data on the precise whereabouts of tagged birds during their movements through the year—we can’t wait!!