Tuesday, 24 February 2015

Bird Ringing 2014

Our "Constant Effort Ringing Scheme" is part of a 25 year old programme run by the British Trust for Ornithology. The idea is that you put in exactly the same effort each year so that the catches are comparable year on year, but the weather often intervenes.

2013 was a terrible year. Only just over 300 birds were caught. This put us into a real spin because our management work is supposed to increase the bird population, not halve it!

Baby long-tailed tit
by Katie Fuller.
In 2014 our team of volunteers included Ian Dillon, Katie Fuller, Rosemary Dillon, Maureen Reeves, Kelly Thomas, Andrew Stanbury, Andrew Tongue, Kevin Middleton and Saimon Clark. The made 12 visits of 6 hours using 140 m of net.

What a relief! About 440 birds were caught, including 399 birds of 27 different species, including two Cetti's warblers. That's good news for us but, not all species did as well as our long-tailed tits that had a bumper breeding season. Reed warblers, garden warblers and blackcaps did well robins and blue tit's didn't. Willow warblers really had a bad year, with fewer adults returning and fewer chicks produced.

Willow warblers nest on the ground in low scrub, so could it be that our scrub areas are getting too tall or that our ground cover is getting too thin? The BTO suggests that there is something bigger going on here, because the Paxton result is part of a national decline.

Young nightingale by Katie Fuller.
I'm always interested in where our birds go when they leave here and nowadays we think we know where most of them winter. For example, our blackcaps go to Spain and Portugal, but this year we learned that one of ours had been caught by a ringer at Punta Blanca on the North African coast across from Gibraltar.

Ringing can also tell you how long birds live. One of our re-trapped dunnocks was caught in 2007 so it was at least 7 years old in 2014.

Our ringers are so keen that they come back for a few visits each autumn in order to catch birds that are coming through on migration. We usually get loads of blackcaps and other warblers in the nets that birdwatchers are hardly aware of. This is because these birds don't sing and usually feed in the the early morning, rest up in the afternoon and migrate onwards at night.

The Rangers and Friends are extremely grateful to the team for their work, especially since it is done by volunteers. The results are very useful in guiding our current and future management of our site and the BTO uses the data to monitor national and international trends.