Given how awful the weather has been recently, I am somewhat surprised that we have managed to get out as many times as we have since the weather prevented us from carrying out Winter CES 3 in mid-December. Since then we have managed to get out just once a week, instead of the usual twice until this week. This was our third session since, and inclusive of, our session on New Year’s day.
The team today comprised myself, Rosie (for once able to stay for most of the session), David and Laura, with both Adam and Daniel. It was a decent session: we met at 7:30, had the nets open by 8:30 and started processing birds straight away. The first bird out of the net was a male Chaffinch. Although it didn’t have any sign, that I would recognise, of Fringilla papillomavirus (FPV), it’s left leg was withered, black and had clearly been broken previously and not healed properly. I showed the bird to the team, so they could see that it was an old injury, but I also decided that, even though the right leg was fine, if I ringed it, somebody else seeing it might decide that ringing had been responsible for its injuries, so I released it some way away from the ringing site, as I didn’t want to catch it again.
We had a steady supply of birds throughout the morning, particularly around the feeding station. As expected, the majority of the birds were Blue and Great Tits. Unfortunately, there was no sign of any Redwing, Lesser Redpoll or Siskin. At least, unlike Thursday at Ravensroost, we weren’t taunted by Redwing flying around the site but not hitting the nets. However, unlike Monday at Webb’s Wood, where we did have 47 birds but from only six species, we did have a bit more variety.
Rosie got to extract her first Great Spotted Woodpecker. We did hear a couple about the place, as we have pretty much at every site for the last few months, but without us catching any. There were also Nuthatch calling, and doing their slow, occasional, staccato drumming, but we didn’t manage to catch any.
The list for the day was: Great Spotted Woodpecker 1; Blue Tit 7(13); Great Tit 5(11); Coal Tit 4(2); Marsh Tit (3); Wren 1; Dunnock 1; Robin 1(1); Chaffinch 1(1). Totals: 21 birds ringed from 9 species and 31 birds retrapped from 6 species, making 52 birds processed from 9 species.
For once, my highlight of the day was a Blue Tit: S395508 was ringed as a juvenile on the 6th July 2016. It has been retrapped on four further occasions, the last being today: making it 7.5 years since it was ringed. The oldest known Blue Tit was 9 years and 8 months since ringing, so it has a couple of years to go yet to beat the record. It is four years since we last recaptured the bird. Every capture has been at Somerford Common, so one wonders where it has been in the interim.
Having started on a sad Chaffinch story, I am going to finish on another. The retrapped Chaffinch that I processed was ringed three years ago. We are very careful about ringing Chaffinch, because of FPV. If there is any sign of the infection, anything other than fresh, healthy, pink legs, we do not ring them. Unfortunately, since ringing this bird has developed the disease. Both legs are affected. I decided not to try to remove the ring, as this would almost certainly have caused some damage to the bird above and beyond what it is currently having to deal with. One thing about FPV: it does not seem to adversely affect the birds until it reaches the end stages and it starts to lose the limbs. I actually measured the wing and weighed the bird: both were well within expected norms. The bird weighed in at 21 grams: the same weight as the healthy bird that we ringed during the session. Some ringers choose not to ring Chaffinch at all, in case they get FPV. My personal view is that if we catch them, and they are clean and showing no signs of infection, we should ring them. Even if they subsequently develop FPV, the ring is not going to adversely impact any more than the infection and, if one wants to potentially study survival in birds affected by FPV, there has to be a means of identifying the individual birds.
Anyway, we started closing the nets at 11:30, as numbers had tailed off again, took down the nets and packed away the ringing station and were off site by 12:30.
Ringing In The Braydon Forest & Beyond 