After a (normal!) dry summer in the meadows along the Severn above Gloucester, most of the pools at the Gloucestershire Wildlife Trust’s two reserves at Coombe Hill and Ashleworth Ham had dried out; in September and early October the only extensive area of open water was on the Long Pool at Coombe Hill, which was attracting small numbers of Teal and a few Snipe, but not the numbers of ducks commonly found when the fields are flooded.
All this changed last weekend, when the level of the River Severn rose sharply, reaching 10.02 metres at Haw Bridge, a level not seen since last February. When the Severn is this high, its smaller tributaries (e.g. the Chelt, and the Deerhust and Leigh Parish drains) cannot flow out into the Severn and so flood back, filling the ditches and covering some of the meadows with a shallow film of water, very attractive to ducks and geese. Last Saturday the fields were dry, but by Tuesday some were lightly flooded. How the water birds get the message so quickly, nobody knows; but by Tuesday, Wigeon numbers were up from 70 to 640 and Greylag and Canada Geese numbers were over 400; this tendency has continued today. Although the Severn level is now dropping again (until the next rainy period at least), it has not subsided enough for the tributaries to discharge, so floods are slightly more extensive on the meadows(though aboslutely normal for the time of the year, and not posing any danger). Numbers of Wigeon have now exceeded a thousand and there are more than 600 geese at Coombe Hill, presenting a fine spectacle from the rebuilt hide. In addition, there are small numbers of other duck species, notably Teal and Mallard, with the odd Pintial and Shoveler, though no very large numbers of the latter yet. Wigeon are autumn arrivals from northern Europe; had they come up from the Severn estuary? Or were they newly arrived birds which happened to find suitable habitat conditions? The Wigeon flock includes one easily recognisable individual, a part-albino (or leucistic) female; perhaps by checking on the presence of this bird, we shall be able to understand the movements of the flock better.