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
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