BOUDEWIJN T & KUIJPERS JWM (1985) Short contributions: Do Pochards Aythya ferina of the Haringvliet feed on Lake Grevelingen?. LIMOSA 58 (4): 163-163.

Common Pochard Aythya ferina During the months August to November, up to 20 000 Pochards are staying on the eastern part of the former Haringvliet estuary, now a freshwater lake. The feeding activity of the birds on the Haringvliet is very low. On the evening of 1 November 1984, large groups of Pochards were seen flying in the direction of Lake Grevelingen, a stagnant saltwater lake (fig. 1). Possible food sources in Lake Grevelingen are eelgrass and the invertebrate Idotea chelipes, which both reach a large biomass in the early autumn. The biomass of invertebrates and aquatic plants in the Haringvliet is too low to feed such large numbers of Pochards during several months.

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