maanantai 15. kesäkuuta 2015

SPRING 2015

Text: Ari Linna and Liisa Puhakka

Dear readers of the Bird Brigade blog. This summary wraps up the last period of the Örö Bird Brigade year, spring 2015. As of June 2015, the island now welcomes all tourists, and while birdwatching in general at Örö Island, as part of the Archipelago National Park, is hopefully merely starting, our mission as a “vanguard” is now at an end.



The period March–May continued in the same vein as the previous winter and autumn: after a short and mild winter, the thermic spring had started in Southern Finland already in February, more than a month earlier than the 30-year average. The daily average temperatures were over 0 C, varying between 0 and 10 C. The mild temperatures meant that snow cover was non-existing; the only harsh weather feature was frequent strong wind from the SW. With practically no ice cover on the Baltic Sea in the outer Finnish Archipelago, Mute Swans (Cygnus olor) didn’t have to leave Örö shores to seek open sea (daily counts varied between 60 and 106 in March), and three Whooper Swans (C. cygnus) had stayed put over the winter at the unfrozen Balget Bay. Some individual Black Guillemots (Cepphus grylle) didn’t migrate either, and instead only changed their gray-white winter plumage to the white and black breeding plumage.

A few hundred Mew Gulls (Larus canus) and Herring Gulls (L. argentatus) invaded Örö waters in the beginning of March, joined in smaller numbers by Greater Black-backed Gulls (L. marinus); a few Black-headed Gulls (L. ridibundus) were seen on migration. Passerines were scarce in the first half of March with Goldcrests (Regulus regulus), tits (Parus spp.), Eurasian Treecreepers (Certhia familiaris), Common Chaffinches (Fringilla coelebs), European Greenfinches (Carduelis chloris), Common Redpolls (C. flammea), European Siskins (C. spinus), Parrot Crossbills (Loxia pytyopsittacus) and Eurasian Bullfinches (Pyrrhula pyrrhula) observed, while some waterfowl, Northern Lapwings (Vanellus vanellus), Eurasian Skylarks (Alauda arvensis) and Stock Doves (Columba oenas) started their visible migration in the very beginning of March. The total amount of bird species observed per trip increased from approximately 30 in January-February to approximately 50 in March, peaking at 85 in April and 103 in May.

Our brigadiers and the periods they stayed at Örö were: Ina-Sabrina Tirri, Jouni Saario, Roland Vösa and Osmo Kivivuori March 5th-9th; Ilkka Sten and Pirkko Kara March 16th-19th; Riitta Honkaranta, Mauno Mustakangas, Heimo Mänty and Outi Sallinen March 23rd-26th; Ina-Sabrina and Antti Kause April 2nd-6th; Mauno Mustakangas and Olavi Nurmi April 20th-23rd; Oskari Härmä April 30th-May 4th; Mauno Mustakangas May 15th-18th, and Harri Wallenius May 22nd-25th. Their trip reports summarized here and found in full (in Finnish) elsewhere in this blog highlight the human aspect behind each observation: the species ID’s and counts jotted down in the notebooks and keyed in to BirdLife Finland’s Tiira database only tell what was seen; these reports aim to bring to light also how they were seen.

March

Ina-Sabrina, Jouni, Roland and Osmo arrived at Örö on the evening of March 5th, with a beautiful sunset over the open sea, stirred only by a mild wind. This loaded them with optimism and expectations of a vivid migration for the next morning.

Sadly enough, rain and drizzle, carried by a heavy wind, swept over the island and our birdwatchers throughout the next day. The walls of a building near Södernäbben offered some shelter while the group scanned the sea. In spite of the unpleasant weather, Red-throated Diver (Gavia stellata) was added to the daily list, and the SW-shore introduced another weatherproof fellow, the toughest pipit of the Finnish territory, Rock Pipit (Anthus petrosus). Even winter observations of this species at the outer fringe of the Finnish archipelago, from Cape Hanko to Utö and Cape Rihtniemi at Pyhämaa, are if not common, quite regular.

On March 7th, the visible world was reduced by a dense fog to a 200 meter radius around our bird watchers. At noon, when the wind had sped up to 13 m/s, the fog was pushed away slightly increasing the visibility a bit. Common Eiders (121) and Red-breasted Mergansers (18) with some additional Long-tailed Ducks (Clangula hyemalis), Common Scoters (Melanitta nigra), Velvet Scoters (M. fusca) and a single Razorbill (Alca torda) were detected as the first migrating waterfowl of the season. Osmo persisted at Södernäbben slightly longer than the others, with a very nice reward, a female Steller's Eider (Polysticta stelleri) saluting by flyby. This species, previously a common winter resident in the Baltic Sea, especially in Estonian waters, has become significantly more rare in the area, and is currently observed only occasionally during the arctic migration in Finland. Definitely a highlight of the day for Osmo!

The heavy 14 m/s SW-wind continued on March 8th, and though staying at Södernäbben tested the brigadiers’ field stamina – some might even say their senses – all the waterfowl from the previous day was still observable. Örö’s first Common Ringed Plover (Charadrius hiaticula) of the spring was seen taking off from the shore, heading east. Quite in line with an observation of the same species at Vedagrundet shore, Cape Hanko, later the same day (10 AM). According to BirdLife Finland´s Tiira database they were the first observations of this species in Finland for the season – both sightings could even be of the same individual.

On March 9th, the wind had calmed down, reflected by some newcomers for the spring´s list, such as Common Shelduck (Tadorna tadorna), Eurasian Wigeon (Anas penelope), Stock Dove, and Western Jackdaw (Corvus monedula). The late indicators of the past winter, Bohemian Waxwings (Bombycilla garrulus), were still present as a flock of 17. Later in the spring, only individual birds were observed.

Ilkka and Pirkko shared Örö with Kari Hiivola and Jouko Högmander, from Metsähallitus. Kari and Jouko conducted a pilot netting project for Long-eared Owls (Asio otus), catching and ringing three individuals on March 17th. It is unsure if the owls belong to a local population, if they had overwintered at Örö, or if they were just passing the island on their migration back from their wintering grounds. Kari mentioned that the numbers of Long-eared Owls caught on the mainland peaked a couple of weeks later, in the first days of April. Even that is a bit early, if compared with Sõrve Bird Station at Saarenmaa, Estonia: in their 10-year data, on average only half of the spring season’s Long-eared Owls are caught by the beginning of April.

During the evening and night of March 17th, Ilkka, Pirkko, Jouko and Kari enjoyed an exceptionally bright display of Northern Lights. Under the beautiful play of colors on the sky, survival games among the Örö wildlife carried on undeterred. The Long-eared Owls seem to be the middlemen in the predator chain, themselves prey to the local Eurasian Eagle Owls (Bubo bubo). The small yellow feet found in an Eagle Owl pellet back in November were tentatively identified as Long-eared Owl feet, and during the second night of Kari and Jouko’s netting project, their decoy owl figure was attacked by an Eagle Owl. The perpetrator itself was quick to flee the scene, leaving only nail marks on the figure and a big hole in the net.

Strong winds from the northern directions delayed the migration, and for many migratory ex-pats it was still much too early to return as well. However, 21 Canada Geese (Branta canadensis) flying east, a pair of leking Northern Pintails (Anas acuta), two Grey Herons (Ardea cinerea), the increased number of Common Blackbirds (Turdus merula, 30), and a couple of wandering Fieldfares (T. pilaris), Redwing (T. iliacus) and Mistle Thrush (T. viscivorus) signaled the arrival of spring.

Pushing against a strong SW-wind, M/S Stella carried Riitta, Mauno, Heimo and Outi to the northern quay at noon on March 23rd. Stella made its maiden voyage to Örö principally to transport workmen, tractors and diggers. Building the infrastructure was in full swing all around Örö, with e.g. the guest harbor at Gölen Bay (southern harbor) being constructed to accommodate the anticipated influx of tourists.

One of the relatively late migrating species, Lesser Black-backed Gull (Larus fuscus) had also arrived and welcomed the brigadiers to Örö. A somewhat colder welcome was provided by the elements, as the Brigadiers, unsheltered on the quay, were drenched by a downpour of sleet. The total amount of bird species listed in the afternoon rose to 23.

Riitta, Mauno, Heimo and Outi spent the first three hours of the following morning at the sunny Södernäbben. A strong wind from SW made the weather feel cold, but that didn’t seem to bother Common Eiders (Somateria mollissima). 400 of them formed the first observed migration, most of them heading north, some east. Bean Goose (Anser fabalis), Common Buzzard (Buteo buteo), Common Kestrel (Falco tinnunculus), Merlin (F. columbarius), Common Woodpigeon (Columba palumbus), Woodlark (Lullula arborea) and Robin (Erithacus rubecula) were added to the list of the spring´s first observations, as well as two Common Cranes (Grus grus) seen on March 25th. A strong eastern wind carried 71 more past Örö the following day. The daily counts for Sea Eagles (Haliaeetus albicilla) rose to 7–11; during the Brigadiers’ previous trip their numbers were 2–7. One of the Sea Eagles was seen doing some in-flight weight training, carrying a three-meter long tree branch presumably to be used as nest-building material. The weight, however, proved eventually to be too much, and the eagle dropped the branch, opting instead for smaller building blocks.

The feeder at Sotka was still serving well: the enthusiasm (or need for nourishment) was shared by Eurasian Bullfinches (2, not seen in April anymore), an individual Linnet (Carduelis cannabina), an occasional Eurasian Nuthatch (Sitta europea) and some tits plus Chaffinches (Fringilla coelebs); the reddish-brown Bank Voles (Myodes glareolus) complemented the feeding assemblage.

Along with the 50 bird species, many of them migratory, other highlights of the trip included bats found hibernating in the island’s bunkers, and on March 26th a beautiful halo phenomenon, with a clear 22° circle and side-suns, a dim 46° circle and a short segment of a parhelic circle (A picture can be seen at the end of their trip report).

April

Ina-Sabrina and Antti arrived at Örö on the afternoon of April 2nd, Holy Thursday. Common Eiders were numerous along the seven nautical miles from Kasnäs to Örö, and on the island itself, an Oystercatcher (Haematopus ostralegus) and two Eurasian Woodcocks (Scolopax rusticola) were jotted down in the Brigadiers’ notebooks. The conditions at Örö reflected the face of Easter throughout the outmost archipelago of Finland, as experienced by Ari during over 20 years at Kökar, Aland Islands - this is the period where the northern latitudes still try to resist the irresistible, the beginning of spring and the thermic growth season. The battle between winter and spring is fought with sleet and crocuses, the latter eventually prevailing over the former. This year, on Finland’s south coast, the daily average temperatures rose permanently above +5 C (within a 10 day control period) on April 7th – before that, Ina-Sabrina and Antti had to endure the last attack of winter in the form of chilly northern winds and some rain and sleet on April 4th and 5th.

The morning of April 3rd dawned with the temperature at +3 C and the wind blowing from the north at 7 m/s; luckily the forest at Södernäbben offered some shelter from the wind. Common Eider migration passed the island at close range on all five days of the trip, with 188, 1082, 1086, 221 and 1080 migrating individuals observed on April 2nd – 6th. Their main direction was east on April 3rd and 4th, with a minor portion heading north on the following two days. Quite a few Eiders stayed also local at the same time, the daily counts being 500 – 1700. The second-most numerous seabird was Red-breasted Merganser (Mergus serrator), 20-80 seen daily. Five Shelducks were seen, and Common Ringed Plovers were feeding on the nearby islets, sharing them with a seal pup. Some passerine migration, heading curiously SW, was observed. It consisted of a few Meadow Pipits (Anthus pratensis), Rock Pipits, White Wagtails (Motacilla alba), Chaffinches, European Greenfinches (Carduelis chloris), European Goldfinches (C. carduelis), Common Linnets, Common Redpolls, Yellowhammers (Emberiza citrinella) and Common Reed Buntings (E. schoeniclus). An unexpected sound alerted Ina to a Black Redstart (Phoenicurus ochruros) perching on a pole. As is common to this species, the bird quickly disappeared – either to take shelter or to chase the next insect. The local birds by the 12 inch battery, the moist grove environment and the village, repeated what was learnt from the previous spring as its indicative fauna: the singing of three Eurasian Treecreepers and various Robins was complemented with Wrens (Troglodytes troglodytes) and a Lesser Spotted Woodpecker (Dendrocopos minor).

On April 4th, the weather was clear and visibility excellent for most of the day, with only some sleet in the morning and light rain later in the day. Two Gadwalls (Anas strepera) passed by toward north, two more could be found behind the islets as local ones; some Common Teals (A. crecca) and Eurasian Wigeons were at site and three Smews (Mergellus albellus), some Common Buzzards and a small flock of Lapwings passed Örö in the east. More than a hundred Chaffinches and plenty of Blackbirds had landed into the 12” battery village.

On the morning of April 5th, there was a hint of frost on the ground, and a northern wind was still blowing hard. The island harbored fewer birds than on the previous day, the tallies of e.g. Chaffinches and Blackbirds were considerably smaller. No Woodcocks were observed – definitely not for lack of effort by the Brigadiers, since the Big Island Bird Day, a yearly competition between islands in the Finnish archipelago, took place that day, with our Brigadiers now adding Örö to the race. An individual Shelduck, a flock of Bean Geese, a couple of migrating Sparrow Hawks (Accipiter nisus) and a Common Crossbill (Loxia curvirostra) were newcomers to the trip list, and a total of 86 Cranes were recorded, 69 of them in a single flock. At the end of the day, the Brigadiers’ day list consisted of 63 species. Jurmo and Hanko bird observatories both reported one species more; none could however compete with the winners, Rönnskär Bird Observatory and Kökar.

April 6th dawned sunny, with a calm sea. This might not have been appreciated by migrating Eiders, at least based on experience from the western coast of Finland. According to Jukka Sillanpää, who conducted a seabird count at Pyhämaa, Cape Rihtniemi, on the same day, a dead calm sea means generally poor migration for Eiders there, but heavy wind and waves catalyze a good flow. The breeze rose at Rihtniemi and Örö in the late morning, and the total count of Eiders by noon was 2640 at Rihtniemi; at Örö the count was 889 individuals heading east and 191 north.

A winter-plumaged Red-throated Diver (Gavia stellata), a Red-necked Grebe (Podiceps griseigena), Razorbills and Black Guillemots were the bird-dots on the peaceful sea, and an Asio-owl landed on a nearby islet. Migrating passerines continued to head SW; three Woodlarks and a Long-tailed Tit (Aegithalos caudatus) were among the goodies at Södernäbben, and the second Black Redstart for the trip, observed in the village, nailed the sum of bird species of the trip to 86.

May

Mauno’s trip to Örö on May 15th-18th had this spring’s highest species count, 103, and added Bar-tailed Godwit (Limosa lapponica) and Common Moorhen (Gallinula chloropus) to the Brigadiers’ species list. There was originally some uncertainty about the Moorhen ID, with original tentative ID’s of Little Crake (Porzana parva), but luckily Sampo Kunttu and Lauri Nikkinen, who happened to be visiting the island at the same time as Mauno, managed to grab a sound recording which was later used to confirm the ID.

The weather was very changeable on May 15th, with sunshine interspersed with light rain. A heavy-ish S/W wind meant there was little migration to be observed; a Rough-legged Buzzard (Buteo lagopus) was, however, seen hovering in the wind. Passerines observed during the day included e.g. Thrush Nightingale (Luscinia luscinia), Common Redstart (Phoenicurus phoenicurus), Song Thrush (Turdus philomelos), Blackcap (Sylvia atricapilla), Lesser Whitethroat (S. curruca), Common Chiffchaff (Phylloscopus collybita), Willow Warbler (P. trochilus) and Common Chaffinch. A Eurasian Woodcock was seen performing its roding flight later in the evening – unfortunately, no owls were seen or heard.

Migration was scarce on May 16th as well, a few White-winged Scoters and one Peregrine Falcon (Falco peregrinus) being the highlights of the clear but windy morning.

Migration rates perked up somewhat on May 17th, with e.g. a couple hundred Divers (Gavia spp.) passing the island – the largest flock being 46 Black-throated Divers (Gavia arctica). During the morning, Mauno was able to add Arctic Skua (Stercocarius parasiticus), Great Cormorant (Phalacrocorax carbo), Ruddy Turnstone (Arenaria interpres) and Yellow Wagtail (Motacilla flava) to his species list. A flock of 50 Dunlins (Calidris alpina) occupied an islet off Södernäbben, and a pair of Cranes were seen at Storviken – maybe they have a nest there?

Changing the routine a bit, instead of observing the morning migration from Södernäbben, Mauno headed to the northern cape of the island on the morning of May 18th. This decision proved fruitful: almost as soon as he arrived, a flock of over 300 Barnacle Geese (Branta leucopsis) passed the cape heading NE. Several more flocks followed; the total number of individuals was 1390. The birds flew very low over the sea, and would likely not have been visible from Södernäbben.

This was Mauno’s eight trip to Örö as a Brigadier, and raised his personal Örö list to a whopping 138 species. Even though this trip was his last as a Brigadier, by Mauno’s own words, ”In the future I will visit the island many times more, Örö is such a wonderful place!”

The final Brigadier to visit Örö was a first-timer, Harri Wallenius, whose trip on May 22nd-25th brought the total Örö Bird Brigadier species list from 188 to a final 190. The last two additions to the list were Collared Flycatcher (Ficedula albicollis) and, maybe somewhat surprisingly, Common Rosefinch (Carpodacys erythrinus). The Collared Flycatcher was a second-calendar-year male, with a prominent forehead patch, a full collar, and a white rump. Altogether the trip list consisted of 87 species. Harri recorded the Brigadiers’ firsts of 2015 of Icterine Warbler (Hippolais icterina), Garden Warbler (Sylvia borin), Spotted Flycatcher (Muscicapa parva) and last but not least, the ultimate sign of summer in Finland – the screeching calls of Common Swifts (Apus apus).

Final tallies

During the 14 months from April 2014 to May 2015, the Örö Bird Brigadiers visited Örö 29 times, accumulating a total of 254 observer days. Our final species list includes a total of 190 bird species; the highest trip count was 108 spp. (May 2014), with three other trips exceeding 100 species.

We would like to extend a thank you to Metsähallitus for this opportunity to get a sneak peek into Örö as part of the Archipelago National Park. It has been enlightening and rewarding to have had a chance to take part, albeit in a small way, in this change of eras at Örö.

A big thank you goes to all our 31 Brigadiers, listed below with their total days spent on Örö. Hopefully for each Brigadier these are only their first 4-30 days spent on Örö, with several multiples more awaiting in the future!

Örö Bird Brigadiers, in alphabetical order:
•    Hannu Friman (4)
•    Jari Helstola (10)
•    Riitta Honkaranta (4)
•    Oskari Härmä (9)
•    Esko Joutsamo (4)
•    Pirkko Kara (4)
•    Antti Kause (5)
•    Osmo Kivivuori (20)
•    Kimmo Kuusisto (5)
•    Kirsi Leiri (4)
•    Ari Linna (18)
•    Jouko Lundén (8)
•    Tapani Missonen (16)
•    Mauno Mustakangas (30)
•    Rasmus Mäki (5)
•    Heimo Mänty (8)
•    Mikael Nordström (5)
•    Aarni Nummila (8)
•    Olavi Nurmi (10)
•    Timo Nurmi (4)
•    Mikko Oivukka (4)
•    Tarja Pajari (8)
•    Liisa Puhakka (15)
•    Jouni Saario (5)
•    Outi Sallinen (4)
•    Ilkka Sten (8)
•    Raisa Tanner (10)
•    Ina-Sabrina Tirri (10)
•    Roland Vösa (5)
•    Harri Wallenius (4)

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