Marsh Warblers are are summer visitors to much of the mid-latitudes of the Western Palaearctic and follow an easterly migration route to wintering grounds in south-eastern Africa. Small numbers currently breed in northern France and the United Kingdom, where there has been a marked decline since 1950.

Ringers have provided the majority of the Bailiwick records of Marsh Warbler. The first Bailiwick and Channel Island record was a bird trapped at La Fougeraie in Sark on 16 May 1974, and Philip Guille subsequently trapped another there on 7 July the following year, a remarkably early date for an autumn migrant. On Guernsey, it was another three years before the first record occurred at Les Bordes in August 1977, after which there was a flurry of 8 records in the following five years to 1982, presumably because ringer's familiarity with this species increased. One was recorded in 1980, four in 1981 and a further two in 1982. In 1981 three birds were recorded during the period 21-23 August, one on each day.

These records were spread over the four major wetland areas in Guernsey (La Claire Mare, La Grande Pré, La Grande Mare and the Marais Nord) and were mostly juvenile birds caught on autumn passage.

One of the few significant sight records occurred during the summer of 1982. A bird was seen singing at La Grande Mare between 1-27 June 1982. There was no further evidence of a breeding attempt. DOES ANYONE HAVE MORE DETAILS?

Since 1982 the number of birds recorded in the Bailiwick has fallen dramatically and there have only been one Guernsey record one first-winter bird was trapped at La Claire Mare on 26 August 1996.

[THERE IS A RECORD FROM THE GRANDE PRE ON10 August 1988 BUT THIS DOES NOT APPEAR IN BISSON – REJECTED]