15 May 2015

Old friends welcome in the new CES season

We recently received the following fascinating account of the first CES visit of the year at Foxglove Covert, Catterick, Yorkshire. The first CES visit period of 2015 is now over and we are already hearing stories of how long-term ringing projects can help us learn more about the productivity, abundance and survival of birds in Britain & Ireland.

Tony Crease writes:

The weather plays a major part in any CES day and the start of the season this year was looking as ominous as ever, so much so that juggling the days of the Bank Holiday became an inevitability. With a CES of ten and a half hours, a day of virtual calm is essential.

Monday provided the window of opportunity and 12 ringers from the Swaledale Group turned out for visit 1 of our 23rd CES season. With trees still without leaves after the recent very cold weather, the usually lush habitat was less than ideal for hiding the nets. Nevertheless, we had an interesting day catching 204 birds of 25 species. The first Blackcap and Garden Warbler of the year were processed as well as 29 Bullfinches, 23 Willow Warblers and many of our routinely resident species. What was entirely unexpected was the age structure of the birds, some of which we find are surprisingly long lived.

An incredible 29 Bullfinches were ringed during the session! Photo: John Harding

Among the more common species we processed was a four year old Chiffchaff, Chaffinches that were four and six years old respectively and six Blue Tits from four to eight years old. Even more fascinating was a pair of Willow Tits; the female, who had a large brood patch, had been ringed on the reserve as a juvenile on 9 August 2007 and had been caught every year since – a total of 37 times in all!

As if that wasn't compensation enough for our very early start, to our complete amazement there then followed R084872, a Marsh Tit which had been ringed as a juvenile in the reserve on 10 July 2004. This bird, we believe, must now hold the British & Irish longevity record for that species*; it has been re-trapped 42 times and has been recorded at Foxglove Covert every year since except 2010 and 2013.

The red-listed Marsh Tit is a regular visitor to Foxglove Covert CE site.
Photo by Tom Wallis

Increasingly, we are finding more results like these with several passerines, including Blackbirds, quite often living five years or more. It is a compelling aspect of our ringing activities and one that has improved so much with the introduction of IPMR. We load the birds as we ring them so information on original ringing data is readily available.

While visiting our Tawny Owl boxes recently we found one bird that had been breeding in the same next box for 16 years. It is an intriguing subject and one that continually delivers surprises. Life is full of the unexpected and our feathered friends in and around Catterick provide many thought-provoking examples.

* Note from the editors - the online longevity records will be updated in June / July to include data from 2014. Until then, we are unable to confirm whether this is a new record for this species. Watch this space...

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