Cetti's Warbler have not as yet been proved to breed in North Lancashire. The first record was one ringed at Leighton Moss in October 1995. Singles were also caught there in the autumns of 2007 and 2008. This increased to four in the autumn/winter of 2009/2010.
At least two males were singing throughout March 2010 but the last one was heard on April 3rd. However this autumn has been outstanding for between September 18th and mid October we have caught six birds. Of these four were newly ringed and two were re-traps from previous autumns. One from September 2008 and the other from October 2009.
So are these two birds returning winter visitors? Or did they breed undetected and the four newly ringed birds are locally bred. Certainly there are many suitable areas difficult of access on the Moss where they could have bred undetected. However one would perhaps have expected us to catch young birds earlier in the season.