NLRG was formed in 1957 to help in the study of birds in the Lancaster and District Birdwatching Society area. There are currently 12 active ringers. Species currently being studied include: Pied Flycatcher, Bearded Tit, Sand Martin, Twite, Goosander, Oystercatcher and Grey Wagtail. Migration has been studied for 28 years at Heysham. We welcome anyone who wants to observe, help or perhaps wish to become a ringer. Photo: A Heysham-ringed Twite on the Mull of Kintyre (thanks to Eddie Maguire)

Thursday, 29 December 2011

How Long Do Birds Live?

One of the most fascinating things about ringing over a long period is that you assemble data on how long birds live. I have always kept a file detailing the longevity records of the group. This time of year I search our data base to see if any of the birds we have re-trapped or have been recovered, have improved on the records we have.

I always check out Reed Warbler first for not only do we ring large numbers each year (980 this year), so improving the chances of getting a new record but also because among small passerines Reed Warblers are well known for being long lived. I was not disappointed for we re trapped one this year nine years and 314 days after ringing. This extends the groups record of the oldest Reed Warbler by just 21 days.

I then turn to another frequently ringed species Blue Tit (1910). The oldest this year was one re-trapped seven years and 326 days after ringing. Another record, 120 days longer than our previous oldest bird.

Great Tits are ringed in smaller numbers (920) but our previous record was 13 years and 339 days not only a record for the group but also for the whole BTO ringing scheme. This year's oldest was four years and 74 days so something of a come down.

Coal Tits (380) have been present in good numbers this year and the oldest at 6 Years and 314 days, beat our previous record by 24 days.

Paul in our last posting highlighted a Dunnock at five years 57 days. Very good, but well short of our oldest record of six years and 205 days.

The species we have ringed most of this year is Sand Martin at 2140 with 648 re traps. Our oldest bird was four years and 216 days but our all time record is five years and 355 days.

These are this year's high lights, remember though that except for the Dunnock which was found dead, all the others were re trapped so hopefully are still going strong. One final thought with our data base it took me ca 35 mins to check through all our re traps. In the days before computers with all paper records it would probably have taken me at least 35 hours to check and then I would probably not have been as accurate.

But the last word should go to the birds, think of that Reed Warbler making at least nine journeys back and forth between Leighton Moss and West Africa. Quite a feat for such a small bird weighing just 12 grams or so!

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