With the weather forecast for sub-zero temperatures, but with winter CES session 3 scheduled for this morning, I decided to got to site to see what the conditions were like. Fortunately, it felt warmer than forecast, probably because there was no breeze, and I determined that we could go ahead with the session. I was joined by Ellie for the morning. I knew that a couple of my other trainees were unavailable and that others are currently at the early stages of learning to extract. Fortunately, Ellie is my most experienced trainee, C-permit holder and extremely competent. As the key in cold conditions is to get the birds out of the nets as soon as possible, and to increase the number of checks on the nets to minimise exposure, that can be hard to do with inexperienced trainees, as you frequently have to step in to help them both in extracting and processing. Once in the bags the birds will be fine, but you don’t want them hanging around in the cold in the nets. Equally, in order to be able to process birds efficiently, and get on with net rounds in a timely manner, experience is key. In the event, I am pleased to say that none of the birds we extracted and processed this morning showed any signs of cold stress, and none had to spend time being warmed up before release.
Despite keeping the nets shut until they were all erected, we did have three birds in the nets before they were properly opened: a retrapped Marsh Tit and Great Tit and an unringed Chaffinch. Subsequent rounds were a bit busier but, around about 10:00, a freezing mist started to affect the nets, they became highly visible with a coating of rime, and the catch dropped right away. We closed the nets at 10:30 and attempted to take down. The nets were heavily rimed, frozen and very heavy and bulky. It was impossible to actually put them back into their net bags, such was the additional volume created by the coating of ice. Instead we tied the ends and then bundled them into our large carry bags. Back at the car I put them into the carry box I use for my bird bags. They are currently sitting in that box, in my kitchen and, four hours later, are still thawing out.
In the just over two hours we had the nets open we caught 34 birds: Nuthatch 1; Blue Tit 1(5); Great Tit 2(10); Coal Tit (3); Marsh Tit (4); Wren (1); Robin 1; Redwing 4; Blackbird 1; Chaffinch 1. Totals: 11 birds ringed from 7 species and 23 birds retrapped from 5 species, making 34 birds processed from 10 species. Not bad for such a short session.
It was good to ring our second Nuthatch in consecutive sessions for the site. That takes it to four ringed for the year: the average for this site. The four recaptured Marsh Tits were all ringed as juveniles at this site this year. In fact, two were ringed in CES 1 and one in CES 2. We did catch a second Chaffinch but, unfortunately, it was suffering with Fringilla papillomavirus (FPV), the legs were showing the warty excrescences and it could not be ringed. We did have a brief discussion about whether there could be some method for identifying individuals so that survival with this condition could be monitored. I have, in the past, weighed birds with FPV, and they always fall within the normal weight ranges, but it would be interesting to see how this disease affects survival.
With everything packed away we were off-site by just after 11:00, heading off for a well-deserved warming up.
Ringing In The Braydon Forest & Beyond 