Photo: Red-Warbler Nest (Patrick Lewin)
Twenty-five years ago a dozen pairs of Reed Warblers were ringed in the Trap Grounds reedbed — the largest colony within the city boundary. But conditions on site gradually deteriorated: the water level dropped as scrub willows invaded the site and dead reeds built up. In 2017 we began eradicating the willows, and scything blocks of reeds on an annual rotational basis, and gradually the health of the reedbed has been restored — as testified on 31 May this year, when members of the Oxford Bird-Ringing Group caught 21 birds in two mist nets. Nine of the birds were Reed Warblers, seven of which were males in breeding condition. This suggests that there could be at least seven breeding pairs in the Trap Grounds. The group members also ringed the elusive Cetti’s Warbler, but it was not in breeding condition, so they deduced that it was probably a male that has failed to attract a mate.
