Spring migration of birds, particularly waterbirds and raptors, was monitored from dawn till dusk from an observation point located on the levee on the northern side of the Medvedce reservoir ...(Dravsko polje, NE Slovenia) in three separate years (1-17 Mar 2009; 25 Mar-10 Apr 2011; 28 Feb-12 Apr 2012). In all three years, 42,045 individuals of 89 species (66 waterbirds, 23 raptors) migrated over the site. 38,238 of these were waterbirds. The most numerous species was Lapwing Vanellus vanellus (11,813 individuals), followed by Blackheaded Gull Chroicocephalus ridibundus (10,515 individuals). In total, 3807 migratory storks, raptors and Cranes Grus grus were counted. Harriers (2303 individuals) were by far the most numerous group. The prevailing direction of migration was SW-NE. Half of all migrating birds were observed in the altitudinal belt between 10 and 100 m above ground level. Harriers were mostly observed up to 100 m above ground level, whereas storks, other raptors and Cranes were observed most often in the altitudinal belt between 100 and 500 m above ground level. The highest numbers of waterbirds were observed between 10 and 100 m above ground level. In the first five hours after sunrise, 61.3% of all waterbirds, 44.0% of all storks and raptors and only 20.5% of Cranes were observed. Although other parts of Dravsko polje have never been studied in such detail, it is possible that a significant portion of migrating birds from a larger area gathers at this site. This study confirms the importance of the area for migrating and staging birds, especially for Great Egret Ardea alba, Marsh Circus aeruginosus and Hen Harriers C. cyaneus, Osprey Pandion haliaetus, Crane, Ruff Calidris pugnax and Black-headed Gull that all reached at least 0.1% of their respective biogeographic populations. Internationally significant are particularly the numbers of migrating Marsh (1079 individuals in 2012) and Hen Harriers (408 individuals in 2012), as there are only few sites where these species migrate in such high numbers in spring.
Between April 2007 and April 2008, 40 systematic waterbird counts were conducted on the Drava River between Lake Maribor and the Melje Dam (length 8.5 km, area 155 ha) to determine the specific ...composition, abundance and seasonal dynamics of bird occurrence. Between October and May, counts were conducted every week, whereas between June and September they were carried out once every two weeks. In total, 26,803 individuals of 30 species were counted. The number of waterbirds and diversity of species were the highest from late December to late February, when more than 1,000 individuals were regularly present in the area. Waterbirds were distributed along the river unequally, with the highest number of birds present yearround in the city centre and in the first counting sector of Lake Maribor. The Mallard Anas platyrhynchos and Mute Swan Cygnus olor were recorded during every count, while occurrence frequency was greater than 50% in another 10 species. Dominant species in terms of percentage composition were Mallard, Black-headed Gull Chroicocephalus ridibundus, Coot Fulica atra, Mute Swan, Pochard Aythya ferina and Tufted Duck Ay. fuligula. Mute Swan and Mallard were the only breeding waterbirds in the study area. Both the total number of waterbirds and the highest daily total in the first two counting sectors were greater between October and March 1992/93 than in our study. The decline in numbers was the greatest for Mallard, Pochard and Tufted Duck, while an increase was noted in Mute Swan and Yellow-legged / Caspian Gull Larus michahellis / cachinnans. The total number of waterbirds and the number of some species in the study area were significantly higher than expected solely based on its length compared to the length of the lowland Drava in Slovenia (125.7 km). The study area is conservationally important for Pochard, Tufted Duck and Black-headed Gull
Between the end of February 2007 and mid-February in 2008, 73 systematic surveys of waterbirds and raptors were carried out during 10-day periods at Cerknica polje (Southern Slovenia). The main ...objectives of our research were: to ascertain the abundance and temporal dynamics of the species occurring here, to specify their status, to make a comparison with the past period of systematic data gathering in the 1991-1992 period, to present estimates of the breeding, migrating and wintering populations, as well as to make, on these bases, a nature-conservancy evaluation of the area. Other ornithological data, acquired till the end of 2010, were gathered as well. Between the beginning of May and the beginning of September 2007, the water in the area virtually ran dry (it was retained only in the channels of the streams), while the surface itself was partially or fully icebound from mid-November 2007 till the beginning of February 2008. By the end of 2010, a total of 129 waterbird and raptor species were recorded at Cerknica polje, while in the 2007-2008 period 83 were registered. Dynamics of the species occurrence with more than nine observations made in the area is presented in a greater detail in the species overview. The breeding status was held by 27 bird species, while further seven were forage guests that bred in the vicinity of the study area. Most of the species (118) had the status of passage visitor, whereas those with the status of summer visitor (34) and winter visitor (40) were fewer. Among the recorded species, 34 were accidental and 21 rare visitors. There were 16 winter and seven summer residents, while year-round residents were six. In all 10-day periods of the research period, four species were recorded: Mallard Anas plathyrhynchos, Grey Heron Ardea cinerea, Buzzard Buteo buteo and Kestrel Falco tinnunculus. In more than 90% of 10-day periods, the Great Egret Ardea alba was recorded as well. In the 2007-2008 period, two species were eudominant (Mallard 27.2%, Buzzard 10.1%), whereas another two were dominant (Garganey Anas querquedula 7.4%, Coot Fulica atra 6.4%). Most individuals were registered at the end of March and in early April (up to 1,978 ind.), whereas the greatest numbers of species (48) were recorded in mid-April. Between May and August, the numbers of individuals and species were low owing to the dried up lake. The smallest area of occurrence was occupied by the Cormorant Phalacrocorax carbo and a group of ducks of the genera Aythya, Bucephala and Mergellus. Gulls, egrets, herons, waders, harriers Circus sp. and the Red-footed Kestrel Falco vespertinus occurred in the greater part of the research area. 10 breeders fulfilled the criteria of the species of the greatest conservation importance, two of which (Ferruginous Duck Aythya nyroca and Curlew Numenius arquata) are species of global conservation concern, whereas seven are of conservation concern on a European scale. Among non-breeders, 14 waterbird species and raptors occurred in significant numbers (> 0.1% biogeographical population), five of which occurred at least occasionally with more than 1% of their biographical population. Two species (Red-necked Grebe Podiceps grisegena and Snipe Gallinago gallinago) breed in Slovenia only at Cerknica polje, while further six species have here at least 40% of their Slovenian breeding population
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Pojavljanje vodnih ptic in ujed na območju vodnega zadrževalnika Medvedce (Dravsko polje, SV Slovenija) v obdobju 2002-2008
Between 2002 and 2008, 251 systematic surveys of waterbirds and raptors ...were carried out during 10-day periods. The main objective of the research was to ascertain the numbers and temporal dynamics of the birds occurring at the reservoir and to define their status. During the research period, more than half of the reservoir was constantly under water between March and October owing to the fishfarming purposes, with fields prevailing in its vicinity. By taking into consideration some older data, 115 species of waterbirds and raptors were registered in the area by the end of 2008, 108 of them during the 2002-2008 period. The status of each species is given quantitatively with different categories of their abundance and occurrence frequency, while data for species occurrence dynamics with more than 10 are presented in the species overview. Confirmed and probable breeding was ascertained for 33 species, while another two were confirmed to breed in the vicinity of the research area. Most of the species (100) have passage migrant status; 13 of these were recorded only once in the 2002-2008 period. Five species were present all the year round. The highest number of species was recorded during the two migration periods, in the spring between end of March and the first half of April, in the autumn between the second half of August and early September (mean value of 32-40 species). The lowest number of species, usually around 10, was registered in the winter period, when the reservoir was for the most part empty or frozen over. The total number of individuals was again highest during the migration period, although significantly higher in autumn than in spring. The highest number of birds was usually recorded between the end of August and mid-September (median between 4,500 and 5,000 individuals). During the 2002-2008 period, it was only the Grey Heron Ardea cinera that frequented the reservoir during all our visits, while in more than 90% of our visits the Great Egret Casmerodius albus and the Mallard Anas platyrhynchos were registered. 32 species were observed less than ten times. The three most abundant species, i.e. the Coot Fulica atra, the Mallard and the Black-headed Gull Larus ridibundus, constituted 76.1% of all counted birds. Dominance was higher than 0.1% in 26 species. The Mallard and the Coot were in most of the years eudominant species in the warmer half of the year.
Provider: - Institution: - Data provided by Europeana Collections- - All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain ...Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
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