In the summer of 1969 the farm ponds within the parish of Kimbolton, Huntingdonshire, were surveyed to assess the rate at which they are disappearing. This area of approximately 5,000 acres (2,000 ha) is now mainly mixed farmland. It includes the Kimbolton Estate, which consists of woodland and parkland as well as arable and pasture farmland, and also a disused airfield, now mainly under plough. The whole area lies between the 100 and 200 foot (30 and 60 metre) contours. By comparing the results of the 1969 fieldwork with past Ordnance Survey and other old maps it was found that the number of farm ponds within this parish declined through changes in agricultural practices from 152 in 1890 to 103 in 1950 and then to only 67 in 1969, a loss of 3 5 % in those last 19 years. A general survey of the flora and fauna of the ponds in 1969 showed that most held breeding Moorhens Gallinula chloropus and this led to the more detailed study in 1971 described here. Of the 67 ponds found in 1969, 15 have been excluded from the present analysis. Of these, one had been filled in, four were difficult of access (two of them in town gardens), five had dried out and five were so totally overgrown that the presence or absence of Moorhens could not be ascertained. The River Kym, the stream and any dykes on which Moorhens may have been nesting were also excluded. The remaining 5 2 ponds