Retrap Central: Somerford Common, Sunday, 28th November 2021

As Storm Arwen (is J.R.R. Tolkein getting royalties?) hit with a vengeance on Saturday, we pushed the scheduled session back to this Sunday morning. As a result, I lost the services of a couple of the team, having already lost one to illness, so my grand plan for several nets away from the usual setup was shelved. However, I was joined for the session by Anna and we set our usual nets. I was interested to see whether the storm would have impacted on our catch. I think it probably did: we only caught one finch when we would usually expect to catch two or three species of finch. As it was, the one finch we caught was a good one though.

One of the arguments often trotted out by the anti-ringing fraternity is that the recovery rate is so low. If you are ringing at a migration hotspot then the likelihood of a high, local recovery rate is obviously not going to happen. When, like me, you ring the same sites throughout the year, with just one site that attracts good numbers of passage migrants (Blakehill Farm), then your recovery rate is much higher. Over the nine years that I have worked these sites retrap rate is over 25% per annum. Clearly, with young passerines suffering from a 70% to 80% mortality rate in the six months post-fledging, a 25% recovery rate is pretty good.

Today at Somerford Common, carrying out our second winter CES session there, we caught 40 birds from 9 species: 31 of them were recaptured birds. Primarily they were resident species, and to recapture 5 Marsh Tits in one session was extremely pleasing. However, we also had the excitement of catching our first ever retrapped Brambling. It was ringed at Somerford on the 27th February this year.

Brambling photo courtesy of Anna Cooper

The most venerable bird caught today was a Blue Tit, ring number S580946, ringed as a juvenile 5 years ago.

The list for the day was: Nuthatch (3); Blue Tit 3(17); Great Tit 2(2); Coal Tit (1); Marsh Tit (5); Wren 2; Robin 1(2); Blackbird 1; Brambling (1). Totals: 9 birds ringed from 5 species and 31 birds retrapped from 7 species, making 40 birds processed from 9 species.

One oddity amongst our catch was a Blue Tit with a deformed bill. It seemed perfectly healthy and was a good weight, so it is clearly not suffering as a result:

Blue Tit with deformed beak. Photo courtesy of Anna Cooper.

We closed the nets after our round at 11:30, took down and left site by 12:15.

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