The Data Builds Up

A recent batch of recoveries added a little more to our knowledge of the movements of birds in our area.

A Sedge Warbler originally ringed in Oxfordshire in July 2010 was found breeding at Leighton Moss. This is our first Sedge Warbler recovery from Oxfordshire. By contrast a Reed Warbler also found breeding at Leighton Moss and ringed at Icklesham in Sussex in late August was our 34th Reed Warbler in Sussex.

Sand Martins have been our most ringed species this year with 2101 new birds ringed. We received details of some of the 648 ringed birds we caught while breeding in the sandy banks of the River Lune. These added to the data we already have brings the total recoveries from Sussex to 117, 13 in Kent, 18 in Yorkshire seven in Cheshire but only our second from Wiltshire. Most have been caught at reed bed roosts but a good number have been caught roosting in established colonies as they make their way south,

John

Bearded Tits Suffer While Reed Warblers Prosper

Following the really cold winter and the trashing of 95% of the Leighton Moss reed bed by roosting Starlings we were rather fearful of the effect on these two reed bed breeding species. Both species are the subject of RAS studies

The bad news is that the Bearded Tit population has declined from at least 30 pairs last year to under 10 this year. To date we have only ringed 16 juveniles compared to 104 last year and although we will probably catch more in the September/October period they are obviously well down. To date we have caught/ re-sighted five adult males and only two adult females we usually catch or sight more adult birds in autumn and on the grit trays but the population has obviously suffered. Last year we caught/sighted 49 males and 28 females.

By contrast Reed Warblers are doing well. To date we have caught 222 adult birds (124 new and 96 re traps from previous years) compared to 224 in 2010 and we have a few more weeks to go although adult Reed Warblers start to migrate in August. To date we have ringed 477 juveniles compared to 515 in the whole season of 2010 and we have what is usually the most productive period of August to early September to come- if only the weather cooperates!

The Starling trashing though seems to have had some effect on the distribution of Reed Warblers, with sites that have at least some standing reed producing the bulk of the adult birds.
Another possible effect is that there has been a re-distribution of the breeding population with a number of old adult birds re trapped this year but not in the intervening years. A extreme example of this was P503386 originally ringed in August 01 as a juvenile- re trapped in 07 and twice this year but not in the intervening years. Two birds first ringed in 05 were also re trapped for the first time this year.

John

A Visitor From Lithuania

We have just received details of a ringed bird reported to us by a visitor to Leighton Moss. All he found on January 1st this year was a leg and ring on the path behind the Public Hide. But he realised it was a bit different for it was a Lithuanian ring, number KV76449.

We now know it was a Starling ringed at Ventes Regas Silute Lithuania as a young bird on 16/07/2010. The bird had flown 1546 km, only to end up as a meal for a Sparrowhawk.

This is the third Starling that the group have had reported from Lithuania and gives a clue as to where the 100's of thousands of Starlings which roost at Leighton Moss in the winter come from.

From ringing of Starlings in past winters we have had reports in the breeding season from Russia (11) , Finland (3) Estonia (6) Latvia (3) Lithuania (3) Poland(1) Norway (7) Germany (9) and Denmark (10).

John