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, 6 October 2017

Remarkable day's ringing - Part 2 - Knot

In the previous blog posting I made reference to an article about Knot at Formby on the 22nd September. Here it is!

The West coast of the UK, particularly Liverpool bay and Morecambe bay, are important areas for wintering Knot in the UK.  Additionally Liverpool bay hosts a large summer flock of second year birds.  A lot of Knot have been ringed on the West coast historically (1970s) however relatively few have been caught and ringed in August, September and April.  This leaves some gaps in our knowledge of Knot and in particular we have limited data after the period after their rapid decline in the 1980s.

Knot have been worked on in the flyway for many years and from recent colour ringing studies some interesting things have been observed. Firstly in Winter birds colour marked on passage in Iceland, Norway and those moulting on the Waddensea are arriving in the North West.  Secondly in August, September and April only Icelandic spring passage birds are seen.  A study was started on the Formby to Ribble coast in 2015 to read flags throughout the year - mainly of birds caught on the early spring staging areas in Iceland and Northern Norway and from the moulting and wintering areas in the Netherlands.  An analysis of the WEBS count data showed that there has been an almost continuous decline in the Autumn and Spring populations since the 1970s.  This study showed that it was necessary to catch Knot on the Formby-Ribble coast to answer several questions:

1 - What do the second year birds do after moulting in the North West?
2 - Where do the adult Knot moulting in the North West go for winter?
3 - Have there been large changes in wintering behaviour of Knot since the work 40 years ago?
4 - Do Knot that remain in the North West until April only migrate via Iceland or do some also go via Norway too?

On the 22nd September 519 Knot were individually colour ringed at Formby in an effort to answer these questions. All the Knot marked have an orange flag and a pale blue ring below on the left tarsus. All the flags have a 2 letter engraved code.

Of the 519 birds colour ringed biometrics were taken from 330, of these 3% are known juveniles, 50% are probable 2nd year birds and the remainder are certainly full adults.  With enough resightings of these Knot most of these questions should be answerable.

In total we caught 1,155 Knot on the 22nd September with all birds being released within 4 hours of capture (for most of this time their feeding grounds are covered by the tide).  Of these only 8 had been ringed previously. The details of these are:

SR74689 - Beaumaris (Anglesey) 17/01/2010 First winter
ST10890 - Seal Sands, Teesmouth 24/08/2015 Juvenile
ST32171 - Wainfleet Marsh (Lincolnshire) 17/09/2016 Juvenile
ST32200 - Gedney Drove End (Lincolnshire) 15/09/2016 Juvenile
ST50909 - Ythan Estuary, (Aberdeenshire) 26/08/2016 Juvenile
SV24636 - Heysham (Lancashire) 21/02/2004 First winter
SV33056 - Wig (Gwynedd) 30/01/2006 First winter
SV56579 - Hoylake (Merseyside) 14/10/2012 Juvenile

In the two weeks since the catch over 100 colour ringed Knot have been reported to Jim Wilson (the project coordinator). All of these sightings have come from a single site on the Wirral or within 2km of the ringing site.   Any sightings whether from Liverpool bay or anywhere else are really valuable to help answer the above questions.

Many thanks to the huge number of people who made this catch possible, particularly the MOD, South West Lancs RG, Jim Wilson, Peter Knight, Rose Maciewicz and the large team that assembled on the day.  Also thanks to Ian Hartley for the photo.

No comments: