Halias is known especially for bird rich autumns, when irruptive migration birds (like tits, woodpeckers, nutcrackers, crossbills, owls etc.) aremigrating. On the other hand great numbers of waterfowl, cranes, raptors and waders are seen every year. Halias is a good birding area throughout the year as long as the sea is not completely frozen.
In the springtime the peninsula of Uddskatan doesn’t gather birds in as big numbers as in the autumn and therefore the ringing activities are not continuous. In spring activities are concentrated on observation of the migration. The observatory is usually occupied from the beginning of March untill the beginning of June.
Spring migration usually starts during the first half of March, but it varies slightly depending on how cold the winter has been. In the turn of March and April good migration, consisting of thousands of eiders Somateria mollissima and hundreds of other ducks, can be seen. Several king eiders S.spectabilis are seen every spring. In mid-April thousands of cranes Grus grus migrate over the Hanko peninsula and the biggest day counts exceed 4000 birds. At the same time thousands of finches are migrating and by the end of April the wader migration starts to get better, when oystercatchers Haematopus ostralegus and Tringa- sandpipers start their migration to the arctic breeding areas. In May arctic migration continues with thousands of geese, divers and waders especially in the second half of the month. Although the numbers are usually smaller than in the best places in the eastern parts of the Gulf of Finland, quite a few flocks are seen from Halias. In mid-May the early autumn migration starts when goldeneye Bucephala clangula, eider Somateria mollissima, mallard Anas platyrhychos and goosander Mergus merganser males start to migrate to their western moulting areas. At the end of May several hundreds of migrating goldeneyes can be seen during one morning. At the beginning of June visible migration starts to taper off and there is time to listen the night singers like marsh Acrocephalus palustris and blyth’s A. dumetorum warblers. Every spring is full of surprises and during suitable weather conditions it is possible to observe amazing migration of fifty thousand thrushes or five hundred of Scarlet Rosefinches Carpodacus erythrinus in one day.
Autumn observation is usually started in the middle of July and it continues without breaks untill the beginning of November. Ringing, observation of migration and staging birds are the daily routines. About ten thousand birds are ringed every year at Halias and most of these are tits.
Bird migration is usually weak in June unless it happens to be a year when hundreds of common crossbills Loxia curvirostra move through the area. Autumn migration of waders starts to become stronger in the beginning of July, when many sandpipers start their southward migration. The migration of black-headed gulls Larus ridibundus culminates in mid of July. By the end of the month hundreds of waders can been seen on the bank of Gåsörsudden if the sea level is low (there is no tide in the Baltic Sea). In August sparrowhawks Accipiter nisus, tree pipits Anthus trivialis, yellow wagtails Motacilla flava and swallows and martins start to migrate in bigger numbers and for example up to fifty sparrow hawks can be ringed during one day.
In September the migrating diversity is the highest. Cranes and different species of waterfowl, raptors, pigeons and passerines are migrating in large numbers. The biggest daily counts of cranes are more than 13000 migrating birds. At the turn of September and October the migration of many irruptive migratory bird species usually starts. The biggest numbers of tits and eurasian jays Garrulus glandarius are seen in the first half of October, when thousands of tits and hundreds of jays can be seen. During this time more than a thousand birds can be ringed in one day. Owls are captured with nighttime mist netting through out October. During the best nights more than five species of owls and over 20 individuals can be caught. October is also the best time for woodpeckers, finches and eastern vagrants. Yellow-browed Phylloscopus inornatus and pallas’ leaf warblers P. proregulus are ringed almost every year. In the beginning of November the intense migration starts to weaken. However, good numbers of waterfowl such as goosanders can be seen as late as December. In some years when the rowanberries are abundant thousands of waxwings Bombycilla garrulus and fieldfares Turdus pilaris can be seen feasting on the berries during late autumn and winter.
Over 300 species have been seen at the observatory with many accidental vagrants. Firsts for Finland in Halias has been dusky thrush Turdus naumanni eunomus in October 1980, western bonelli’s warbler P. bonelli in June 2000 and pallid swift Apus pallidus in october 2004. Observed spring rarities are for example great northern diver Gavia immer, pallid harriers Circus macrourus, bee-eaters Merops apiaster, red-rumped swallows Hirundo daurica, tawny pipits Anthus campestris, citrine wagtails Motacilla citreola, collared flycatchers Ficedula albicollis, penduline tits Remiz pendulinus, woodchat shrike Lanius senator, lesser grey shrikes L. minor and many others. In the summer Halias is one of the best places in Finland to see the sandwich tern Sterna sandvicensis. Other summertime rarities are for example grey wagtail Motacilla cinerea, quail Coturnix coturnix and terek sandpiper Xenus cinerea.
The rarest autumn vagrants have been glossy ibis Plegadis falcinellus, ruddy shelducks Tadorna ferruginea, short-toed Circaetus gallicus and steppe eagle Aquila nipalensis, red phalarope Phalaropus fulicarius, short-toed larks Calandrella brachydactyla, siberian Prunella montanella and black-throated accentor P. atrogularis, common nightingale Luscinia megarhynchos, desert warbler Syliva nana, dusky Phylloscopus fuscatus, radde’s P. schwarzi and hume’s leaf warblers P. humei and rose starlings Sturnus roseus etc.
In winter Halias is one of the best places to watch waterfowl, because the Baltic Sea surronding Halias freezes later than lakes, the Gulf of Bothnia and the eastern Gulf of Finland. As long as there is open water in the area swans and other waterfowl try to winter there. Steller’s eiders Polysticta stelleri and even gyrfalcon Falco rusticolus have been several times in winter.
The latest bird observations can be found from the Tiira bird database
(Birdlife Finland) (in Finnish).