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)

Friday, 13 March 2009

Twite update

See previous posting for the background to this

Alan caught 18 Twite today at the Heysham feeding station, including 7 unringed birds, out of 30+ seen.

The retrap data from the other 11 birds is interesting. Most of them were retrapped for the first time since ringing with the ringing dates as follows:
31/10/08 (1)
5/11/08 (2)
26/11/08 (4)
4/2/09 (1)
One was ringed on 5/11 and retrapped on 4/2/09
Two others were both ringed on 31/10/08 and retrapped on 5/11/08 + 16/11/08 and 16/11/08 + 15/12/08 respectively.

Bearing in mind that only FIVE out of the 137 ringed during winter 2008/9 have been previously retrapped twice, it is interesting that two of these have appeared for their third retrap today. This suggests that, in contrast to the rest of the retrap data (& unringed birds), which suggests a wide-ranging metapopulation with individual birds occasionally visiting Heysham, these two (and perhaps the bird retrapped on 4/2) have developed a degree of loyalty to the Heysham feeding station. This is backed up by variable counts (rarely exceeding 30 at any one time) and ringed/unringed percentages

14/3/09 update: Heysham NHW feeding station at 1315hrs
31 Twite with 7 unringed, 23 Heysham-ringed and one ringed in autumn 2008 at Askam in Furness, Duddon estuary. A reading attempt on the latter with 50 x just kept flagging the letter "R"; about as helpful as the "E" when reading British-ringed Black-headed Gulls.

[No flagged/cr Knot/c600 on heliport] (14/3/09)

Pete Marsh

No comments: