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)

Saturday, 12 August 2017

Sedge Warblers on the Move

A report of a Sedge Warbler ringed by the Group on July 25th this year and caught 12 days later in Kent 412 km SE set me looking at all the similar quick recoveries we have for this species. Over the years we have ringed just over 14,000 Sedge Warblers which has produced 172 recoveries most at ringing stations on the south coast with some further a field in France (51)Spain (3) Portugal(1) and Senegal (1).

Our quickest mover was one ringed on August 13th 2004 at 10.00 and caught next day at Coventry at 05.50 a distance of 220 km. Sedge Warblers are night migrants so this gives some idea as to how far they can fly in a night. It weighed 12.7 gms at ringing but only 11.7 on re-capture.

Of other short time(under 10 days) recaptures we have two each at 4 and 5 days,4 at 6 days and one each at 9 and 10 days all along the south coast from Devon to Kent. Other than one in late July all the others were ringed and re-caught in August. Not all the birds we ring are local birds for we have caught three ringed in Perthshire ,two 7 days previously and one 14 days.

Two short time recaptures from France were 6 days after ringing, a distance of 677 km and 12 days a distance of 563 km. Remember most of these are young birds making their first migration at around three months old. Amazing!
John

Wednesday, 9 August 2017

Nest Box Statistics

Further to my last post where the Group had 141 nest boxes occupied by Pied Flycatcher of which 121 were successful I now have data for the occupation rate of Blue and Great Tits in 24 of the woods we record they show some interesting differences.
The 11 woods at lower altitude mainly on the limestone where Ash is the dominant tree species and Pied Flycatchers do not nest Great tits outstrip Blue tits. In total in these woods we had 113 Great tits but only 62 Blue Tits. In contrast in the higher altitude woods with Oak dominant and where Pied Flycatchers also occur we recorded 143 Blue Tits but only 62 Great Tits.
To what extent this is due to the number and size of natural holes is difficult to assess. But the differences occur in comparatively new woods in both areas. Productivity was good as it was with Pied Flycatchers with very few nests lost to predation or dead young in the nest.
John