ROOTH J (1960) Bird-counts 1953-1956 on the Island of Vlieland. LIMOSA 33 (3): 134-159.

The bird-counts on Vlieland are a continuation of those previously taken on the nature reserve De Boschplaat, Terschelling (MoRzER BRUYNS and BRAAKSMA, 1954) . Getting a deeper insight into the causes underlying the qualitative and quantitative differences in he bird-population of the various breeding and haltingplaces on the Frisian Islands is the purpose of this compilation of data. The observed numbers are comparable because each time the census was taken in the same way and on the same route. Thanks to 30 collaborators it was possible to have observations on at least 2 days out of every month, for a period of 3 years. So, at the end of the period of investigation there were data available of at least 6 days a month. In the tables the largest numbers for a month are given. This makes possible a comparison with Terschelling and also gives an insight in the potential significance of the area. In this way the sharp fluctuations caused by different weather conditions are, to a certain degree, neutralized. Especially during periods of high water Vlieland is a very place of refuge for gulls and waders. By this method especially the spring-tide data of this group are included in the tables. P. indicates the known number of breeding couples, but this number is not stated for all breeding birds. Among the 175 species observed there were about 60 different species of breeding birds. These numbers are higher than those of Terschelling, resp. 165 and 40. This is caused by the fact that on Vlieland an inventory was taken not only of the dunes, salt marshes and tidal-flats as in Terschelling, but also of parts of the built-up area, the beach, the pine-forest and both duck-decoy bushes. The Divers and Grebes were mostly seen in the deeper places of the sea around the tidal-flats. The Spoonbills are regular visitors, especially after the breedingseason; they probably originate from a neighbouring colony on Texel. The Brent Geese arrive here later than on Terschelling and their number decreases earlier in the spring too. The food here consists of Zostera nana. Salicomia herbacea. Puccinell.ia maritima and, especially in November and December, of Enteromorpha spec. Since their discovery by LEEGE in 1906 the Eiders have gradually increased their number and in the last few years about 2000 couples have been breeding here. As contrasted to Terschelling the Eiders are seen around the island throughout the year. After the 1956---1957 myxomatosis only one couple of the Marsh Harrier bred here in 1957 and none did so in 1958. The Turnstones were shown to have a great preference for the Posthuisflat, which is overgrown with Enteromorpha; they roll up the slabs of see-weed and then feast on the H ydrobia. some worms and above all on Gammarus locusta. In Winter Woodcocks were regularly observed in the bushes of the Old Duck Decoy. The Curlews, in contradistinction to those of Terschelling, were regularly observed in great numbers in the dunes out of the breeding-season. There is a discussion whether the great number of Bar-tailed Godwits is caused by a preference for predominantly sandy or muddy tidal-flats. During periods of heavy frost hardly any Knots or Dunlins were observed and the other waders were also absent, or only present in small numbers. As on Terschelling Hooded Crows breed here and mixed couples, with Carrion Crows, are found; consequently hybrides were regularly observed. The flocks feeding on the tidal flats, on Vlieland especially the Posthuisf1atscomplex. during several months are given in fable XVIII. together with the data from the Boschplaat-f1ats on Terschelling. The number of fluctuations on Vlie1and is found to be much greater than on Terschelling: a minimum in June of well over half of that of Terschelling in May and a maximum in August which is twice as large. The great differences in August and September ma be explained to an important degree by the greater number of Bar-tailed Godwits. Knots and Dunlins which are then observed on Vlieland. In the end a comparison is made with other high-tide places of refuge in the Dutch part of the Frisian Islands. There are various places where some ten-thousands of migrating waders and waterfowl are observed. Within the Dutch part of these islands some hundred-thousands of migrating birds find an important halting-place. ##### Red-throated Diver Gavia stellata Great Crested Grebe Podiceps cristatus Little Grebe Tachybaptus ruficollis Red-necked Grebe Podiceps grisegena Horned Grebe Podiceps auritus Black-throated Diver Gavia arctica Great Northern Diver Gavia immer Northern Fulmar Fulmarus glacialis Northern Gannet Morus bassanus = Sula bassana Great Cormorant Phalacrocorax carbo Grey Heron Ardea cinerea Eurasian Bittern Botaurus stellaris Mute Swan Cygnus olor Whooper Swan Cygnus cygnus Greylag Goose Anser anser Greater White-fronted Goose Anser albifrons Dark-bellied Brent Goose Branta bernicla Common Shelduck Tadorna tadorna Greater Scaup Aythya marila Red-breasted Merganser Mergus serrator Long-tailed Duck Clangula hyemalis Mallard Anas platyrhynchos Gadwall Anas strepera Common Teal Anas crecca Garganey Anas querquedula Eurasian Wigeon Anas penelope Northern Pintail Anas acuta Northern Shoveler Anas clypeata Greater Scaup Aythya marila Common Goldeneye Bucephala clangula Common Eider Somateria mollissima Black Scoter Melanitta nigra Velvet Scoter Melanitta fusca Western Marsh Harrier Circus aeruginosus Montagu's Harrier Circus pygargus Hen Harrier Circus cyaneus Eurasian Sparrowhawk Accipiter nisus Common Buzzard Buteo buteo Common Kestrel Falco tinnunculus Eurasian Hobby Falco subbuteo Osprey Pandion haliaetus Common Pheasant Phasianus colchicus Grey Partridge Perdix perdix Water Rail Rallus aquaticus Eurasian Coot Fulica atra Common Moorhen Gallinula chloropus Eurasian Oystercatcher Haematopus ostralegus Northern Lapwing Vanellus vanellus Grey Plover Pluvialis squatarola Kentish Plover Charadrius alexandrinus Eurasian Dotterel Charadrius morinellus Ruddy Turnstone Arenaria interpres Common Snipe Gallinago gallinago Jack Snipe Lymnocryptes minimus Eurasian Woodcock Scolopax rusticola Eurasian Curlew Numenius arquata Whimbrel Numenius phaeopus Black-tailed Godwit Limosa limosa Bar-tailed Godwit Limosa lapponica Common Redshank Tringa totanus Common Greenshank Tringa nebularia Ruff Philomachus pugnax Red-necked Phalarope Phalaropus lobatus Pied Avocet Recurvirostra avosetta Red Knot Calidris canutus Dunlin Calidris alpina Curlew Sandpiper Calidris ferruginea Purple Sandpiper Calidris maritima Least Sandpiper Calidris minutilla Little Stint Calidris minuta Sanderling Calidris alba Lesser Black-backed Gull Larus fuscus graellsii Lesser Black-backed Gull Larus fuscus European Herring Gull Larus argentatus Common Gull Larus canus canus Black-headed Gull Chroicocephalus ridibundus Black-legged Kittiwake Rissa tridactyla Gull-billed Tern Gelochelidon nilotica Common Tern Sterna hirundo Sandwich Tern Thalasseus sandvicensis = Sterna sandvicensis Little Tern Sternula albifrons Black Tern Chlidonias niger Razorbill Alca torda Atlantic Murre Uria aalge Atlantic Puffin Fratercula arctica Common Wood Pigeon Columba palumbus Stock Dove Columba oenas European Turtle Dove Streptopelia turtur Common Cuckoo Cuculus canorus Short-eared Owl Asio flammeus Long-eared Owl Asio otus European Nightjar Caprimulgus europaeus Barn Swallow Hirundo rustica Sand Martin Riparia riparia Common Swift Apus apus Eurasian Hoopoe Upupa epops Great Spotted Woodpecker Dendrocopos major Eurasian Wryneck Jynx torquilla Fieldfare Turdus pilaris Mistle Thrush Turdus viscivorus Song Thrush Turdus philomelos Redwing Turdus iliacus Ring Ouzel Turdus torquatus Common Blackbird Turdus merula Northern Wheatear Oenanthe oenanthe Whinchat Saxicola rubetra Common Redstart Phoenicurus phoenicurus Black Redstart Phoenicurus ochruros Common Nightingale Luscinia megarhynchos Bluethroat Luscinia svecica = Cyalnosylvia svecica European Robin Erithacus rubecula Dunnock Prunella modularis Common Whitethroat Sylvia communis Garden Warbler Sylvia borin Blackcap Sylvia atricapilla Lesser Whitethroat Sylvia curruca Willow Warbler Phylloscopus trochilus Common Chiffchaff Phylloscopus collybita Wood Warbler Phylloscopus sibilatrix Common Grasshopper Warbler Locustella naevia Great Reed Warbler Acrocephalus arundinaceus Marsh Warbler Acrocephalus palustris Sedge Warbler Acrocephalus schoenobaenus Icterine Warbler Hippolais icterina Winter Wren Troglodytes troglodytes Spotted Flycatcher Muscicapa striata European Pied Flycatcher Ficedula hypoleuca Eurasian Skylark Alauda arvensis Wood Lark Lullula arborea Horned Lark Eremophila alpestris Meadow Pipit Anthus pratensis Tree Pipit Anthus trivialis Blue-headed Wagtail Motacilla flava Grey-headed Wagtail Motacilla thunbergi = Motacilla flava thunbergi Yellow Wagtail Motacilla flavissima = Motacilla flava flavissima White Wagtail Motacilla alba Red-backed Shrike Lanius collurio Great Grey Shrike Lanius excubitor Great Tit Parus major Blue Tit Cyanistes caeruleus Coal Tit Periparus ater Crested Tit Lophophanes cristatus Long-tailed Tit Aegithalos caudatus Goldcrest Regulus regulus Firecrest Regulus ignicapilla Hooded Crow Corvus cornix = Corvus corne cornix Carrion Crow Corvus corone Eurasian Magpie Pica pica Rook Corvus frugilegus Western Jackdaw Coloeus monedula Eurasian Jay Garrulus glandarius Common Starling Sturnus vulgaris Eurasian Golden Oriole Oriolus oriolus Common Chaffinch Fringilla coelebs Brambling Fringilla montifringilla Eurasian Siskin Carduelis spinus Twite Carduelis flavirostris Unidentified Redpoll Carduelis cabaret/flammea Common Linnet Carduelis cannabina House Sparrow Passer domesticus Eurasian Tree Sparrow Passer montanus Common Crossbill Loxia curvirostra European Greenfinch Carduelis chloris Corn Bunting Emberiza calandra Ortolan Bunting Emberiza hortulana Common Reed Bunting Emberiza schoeniclus Snow Bunting Plectrophenax nivalis Black-headed Gull Chroicocephalus = Laurus ridibundus

[free pdf] [dutch summary]