LEBRET T (1972) Birds of the nature reserves in the Veerse Meer in the first ten years after the closing of the estuary 1961 - 1970. LIMOSA 45 (1): 1-24.

1. In April 1%1 the first estuary in the southwest of the Netherlands has been closed as part of the Delta Plan. The area was named Veerse Meer. There are two nature reserves: the Middelplaten (300 ha) and the Goudplaat (45 ha). The development of the vegetation as far as important for the ornithologist is described. The waters of the Veerse Meer are brackish (9-11 %0 Cl'). During winter (September-March) the water table is lowered to some 0.70-0.90 m below summer level. Some 2000 ha of the waters of the Veerse Meer are a wildfowl sanctuary where no shooting is allowed. 2. The nature reserves are situated in the lower parts of the upper half of the former tidal zone. They consist of former tidal sandflats and two sandbars. It could be expected that the vegetation would develop into thickets of Salix, Phragmites, Cirsium, Epilobium and Hippophae, unless appropriate management measures would be taken in due time. The development of thickets was prevented mainly by grazing by sheep and cattle. Some 30 ha have been sown with grasses. Two islands have not been grazed so far, but grazing of the greater one has been started in May 1971. Reeds and willows have been pulled out by hand in the first years, which method proved successful. Burning of Epilobium was not successful. In March 1971 mowing of some dense stands of Epilobium has been attempted and this method appears to give grasses a better chance. 3. The breeding birds of the nature reserves are listed according to the year of their appearance. Of the original 24 species, 4 have disappeared, 10 new species have immigrated. The sequence of the appearance of the various species is discussed. Both the stage of development of the vegetation and the numbers of potential immigrants may play a role. 4. In some species the numbers before the closing of the estuary are compared with the present numbers. The Sandwich Tern Sterna sandvicensis has disappeared. There is a decrease of the Common Tern Sterna hirundo. Little Tern Sterna minuta, Herring Gull Larus argentatus, Avocet Recurvirostra avosetta, Lapwing Vanellus vanellus and Ruff Philomachus pugnax have increased. 5. The numbers of breeding pairs of some species are shown in diagrams (Fig. 5 and 6). Those of the Veerse Meer reserves are compared with those of the Braakman reserve which has a comparable origin but where no adeaquate management measures have been carried out. 6. The natural conditions of the Veerse Meer reserves - low level, poor sandy soil, brackish water - combined with management measures - eradication of willows and reeds, grazing, burning and mowing - have created favourable habitats for terns, waders and ducks. During the first ten years (1961-1970) these management measures, planned in favour of these species, were successful such in contrast with the laissez faire policy in the Bra:akman reserve. A small decline, however, is visible in some species. It is not clear if this is the beginning of a downward trend. 7. The sowing of grasses appeared successful in attracting large numbers of wild geese. The annual maximum numbers of Whitefronted Geese Anser albifrons and Barnacle Geese Branta leucopsis are shown in diagrams. As no chemical fertilizers have been used so far, the carrying capacity of this type of pasture, however, is probably smaller than in nearby older pasture land polders with a clayish soil. On the other hand the res;erves are practically undisturbed. This partly compensates the inferior quality of the grazing. 8. The mudflats and shallows in the eastern part of the reserve are an important roost where wild geese from a much wider region concentrate during the night. As the distribution of the wild geese largely depends on the distribution of the roosts, this function of the reserve is of more importance than its grazing value. ##### Grey Heron Ardea cinerea Common Kestrel Falco tinnunculus Common Wood Pigeon Columba palumbus European Turtle Dove Streptopelia turtur Common Swift Apus apus European Greenfinch Carduelis chloris House Sparrow Passer domesticus Eurasian Tree Sparrow Passer montanus Common Starling Sturnus vulgaris Barn Swallow Hirundo rustica Common House Martin Delichon urbicum = Delichon urbica Western Jackdaw Coloeus monedula Eurasian Magpie Pica pica Great Crested Grebe Podiceps cristatus Great Cormorant Phalacrocorax carbo Tufted Duck Aythya fuligula Common Pochard Aythya ferina Red-breasted Merganser Mergus serrator Greylag Goose Anser anser Western Marsh Harrier Circus aeruginosus Eurasian Curlew Numenius arquata Common Snipe Gallinago gallinago Short-eared Owl Asio flammeus Northern Wheatear Oenanthe oenanthe Dark-bellied Brent Goose Branta bernicla Grey Plover Pluvialis squatarola Ruddy Turnstone Arenaria interpres Whimbrel Numenius phaeopus Bar-tailed Godwit Limosa lapponica Green Sandpiper Tringa ochropus Wood Sandpiper Tringa glareola Common Sandpiper Actitis hypoleucos = Tringa hypoleucos Spotted Redshank Tringa erythropus Common Greenshank Tringa nebularia Red Knot Calidris canutus Dunlin Calidris alpina = Calidris alpina schinzii Greater White-fronted Goose Anser albifrons Taiga Bean Goose Anser fabalis Barnacle Goose Branta leucopsis Bewick's Swan Cygnus bewickii

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