bluuebunny/crossref_metadata_2025 huggingface dataset:
Hannars etableringsmönster, revirkvalitet samt flytande bestånd i en randpopulation av svart rödstjärt Phoenicurus ochruros
Authors: Andersson Reino
Published: March 2023

The relationship between pattern of territory establishment in males and territory quality was studied in 1983–1994 in a colour-ringed population of Black Redstart in southwestern Sweden. Further, the size of the floating population was estimated as well as its influence on territory establishment. The material consists of 141 establishments of territorial males, distributed on 55 different territories. Characteristics of the habitat and exploitation of territories are described. The competition between different males was studied by removal experiments. Some males were placed in cages, while others were removed and released. The frequency of occupation varied (average 57%), and only 15% of the territories contained singing males each year. Optimal territories were occupied earliest, mainly by adult males. The majority of all territory establishments were made by new, unknown males (73%). Only 18% of the males showed territory fidelity between years. The size of the floating population was 26%, but its influence on territory establishment appeared to be marginal. The removal experiments showed that both adult and second-year males are capable to establish, defend and preserve optimal territories as soon as it is possible. Optimal territories were reoccupied earlier than territories of a lower quality, and adults established themselves faster than second-year birds. In many other studies, replacements were made by neighbours, but the results of the present study did not confirm this pattern. In eight confrontation trials, half of the owners recaptured their territories, while the other dominants were replacement males.
Interrupted moult of adult Willow Warblers Phylloscopus trochilus during autumn migration through Sweden
Authors: Hedenström Anders , Lindström Åke , Pettersson Jan
Published: March 2023

Among passerines a complete moult is carried out annually after breeding in the summer season or, in some long-distance migrants, after autumn migration in the winter season. A few species, such as the Willow Warbler Phylloscopus trochilus, show two complete annual moults. It is often observed that among Willow Warblers on autumn migration passage a few individuals retain one or more old secondaries, hence the moult after breeding has been interrupted. We hypothesise that the frequency of birds showing moult interruption should increase with increasing breeding latitude due to the shorter time available for breeding and moult towards north. Further, we expected a higher incidence of moult interruption in females compared with males because females presumably are more involved in breeding activities. These hypotheses were explored with data on adult Willow Warblers collected at Swedish bird observatories during a nation-wide co-operation project concerning the migration of the Willow Warbler. We found a positive correlation between the proportion of Willow Warblers with unmoulted secondaries and latitude. The proportion of females with moult interruption was higher than in males, and among birds with remaining old secondaries females had more unmoulted feathers than males. We found a rather high proportion of birds with interrupted moult at southern observatories, which we speculate may be associated with birds laying second clutches in some years.
Correlation between some body components and visible fat index in the Willow Warbler Phylloscopus trochilus (L.)
Authors: Lundgren Björn , Hedenström Anders , Pettersson Jan
Published: March 2023

The correlations between some body components and visual as well as chemically extracted fat deposits of migratory Willow Warblers were studied. This study shows that the use of body mass and visual fat index are good predictors of fat deposition in the Willow Warbler. The results also indicate that body water and fat content explain most of the variation of total body mass, followed by carcass-dry mass and pectoralis muscle dry-mass (spring birds). A significant, positive correlation between pectoralis muscle dry-mass and total extracted fat content in spring birds suggests a possible muscle hypertrophy associated with fat deposition. This may be an adaptation to carry heavy fat loads during migratory flights.
Storlommens Gavia arctica häckningsframgång i sydvästra Sverige 1982—1992
Authors: Eriksson Mats O G , Ahlgren Claes-Göran , Fallberg Ronny , Karlsson Göran , Kongbäck Hans
Published: March 2023

The breeding success of Black-throated Diver Gavia arctica was surveyed in 65 freshwater lakes in southwestern Sweden during 1982—1992. The production of young, measured as the mean number of well-grown (half-grown to fledged) chicks per stationary pair, as well as the percentage of stationary pairs producing well-grown young, decreased significantly over the study period. Only in one third of the lakes investigated, the production of young exceeded the estimated minimum level assessed as necessary for the maintenance of a stable population size. A lowered percentage of pairs which initiate breeding, in combination with a decreased proportion of successful pairs producing two well-grown young, indicate a general decline in the physical condition of the birds. Two alternative explanations, reduced abundance of prey or increased exposure to high levels of mercury in acidified lakes, are discussed.
Samhäckande vadare pa strandängar i sydvästra Sverige: Predationsskydd eller habitatval?
Authors: Flodin Lars-Åke , Hirsimäki Henry , Norén Lars-Göran
Published: March 2023

It has been observed that non-aggressive waders breed close to aggressive waders because of the predator protection that the latter may provide. We studied the association, breeding success, and habitat selection of three non-aggressive species (Tringa totanus, Calidris alpina schinzii and Philomachus pugnax) in an area where two aggressive species (Vanellus vanellus and Limosa limosa) also bred. We analysed four predictions that ought to be valid for the non-aggressive species if they obtained protection by breeding close to the aggressive ones: they would (1) breed at the same time, (2) prefer to breed within the territories of the aggressive species, (3) show higher breeding success within than outside the territories of the aggressive species, and (4) not differ from the aggressive species in habitat selection. We found no support for any of the predictions. Instead we found that the non-aggressive species selected higher vegetation for their nest sites. Thus, the better nest protection of higher vegetation was more important than predator protection given by the aggressive species.
Feeding ecology of the Long-tailed Duck Clangula hyemalis wintering in the Gulf of Gdańsk (southern Baltic Sea)
Authors: Stempniewicz Lech
Published: March 2023

The feeding ecology of the Long-tailed Duck Clangula hyemalis was studied in the Gulf of Gdańsk during eight wintering seasons (November–April) 1972–1976 and 1986–1990 (423 food samples). The number of food taxa consumed was at least 28 (23 animal and 5 plant). Long-tailed Ducks fed mainly on bivalves of which Macoma baltica and Mya arenaria were the most important, then Mytilus edulis and Cardium glaucum. Fish, mostly Ammodytidae, and fish eggs were present in ca. every fourth sample. Crustaceans, polychaetes and gastropods constituted the remaining significant prey. Plant food was incidental. Birds selected main food items (3 bivalves) of shell length ca. 11.0–11.6 mm regardless of their different average size found in zoobenthos. Seasonal and some age and sex related differences in Long-tailed Duck diet were found. They consumed proportionally more Mytilus and Cardium in December and January and less later in the season. Crustaceans, polychaetes and especially fish (fish eggs) increased their percent share in the diet in the spring. Adult birds tended to eat more Mytilus and Cardium while immatures ingested more crustaceans. Birds caught in nets set deep (>20 m) fed largely on Mesidothea entomon. Long-tailed Ducks function as first to fourth-order carnivores in the food web of the Gulf of Gdansk. Due to their high numbers and long period of staying they consume considerable biomass of main food prey. Estimated yearly consumption of bivalves amounts to 6 350 tonnes (Macoma baltica–2,100, Mya arenaria–1,700, Mytilus edulis–1,600, Cardium glaucum–950), fish–1,120, crustaceans–400, polychaetes–200, and gastropods–125 tonnes. At least locally, they prey significantly on certain age classes of the most important food taxa.
Fuel deposition and potential flight ranges of Blackcaps Sylvia atricapilla and Whitethroats Sylvia communis on spring migration in The Gambia
Authors: Hjort Christian , Pettersson Jan , Lindström Åke , King J Michael B
Published: March 2023

Spring migration of Palaearctic passerines was studied on Ginak Island in The Gambia, as part of the European Science Foundation network "Palaearctic-African Songbird Migration". In this paper data collected from Blackcaps Sylvia atricapilla and Whitethroats Sylvia communis, which in late March–early April prepare for the crossing of the Sahara desert, are analysed. On a diet of mainly Maytenus senegalensis berries these warblers put on up to 3–4% body mass per day and when ready for take-off 35–40% of their mass consists of fuel for the trip. According to conventional flight-range calculations this gives them flight ranges in still air of maximum 1,200 km, which will not take them unaided across the desert. But predictable tailwinds, usually found at altitudes above c. 2,500 m, may help them to central Morocco or beyond. In addition, recent wind-tunnel experiments have suggested a distinctly reduced drag coefficient for use in the flight-range calculations, and this may extend the still-air range to more than 2,500 km. In that case the desert crossing would be possible also without the help of tailwinds.
Skrattmåsens Larus ridibundus populationsutveckling i Sverige under de senaste 25 åren
Authors: Källander Hans
Published: March 2023

Although starting its northward spread in Sweden earlier, the Black-headed Gull Larus ridibundus showed an almost explosive increase after the Second World War. However, during the last two decades the population has decreased strongly, especially in the agricultural districts of South and South Central Sweden, i.e. those areas which held the majority of the Swedish population. In this paper, data have been compiled by province from various sources (mainly papers and bird reports in local ornithological journals) in an attempt at estimating the size of this decrease and at finding any geographical pattern that might shed light on its cause, or causes. In the main agricultural areas, the decrease of the Black-headed Gull population has been in the order of 70% to 80%, on the island of Öland in the Baltic even more than 95%. Several reports indicate that the decrease started in the species' core areas in the mid-1970s when most of the large colonies diminished or disappeared, but somewhat later in less extreme agricultural areas. The reason for this recent decline is not known. Both deterioration of breeding habitat and predation by mink Mustela vison may explain a certain re-distribution of colonies from eutrophic lakes to offshore islands (and cities and industrial waste land); heavy predation by mink on gull chicks and subsequent abandonment of colonies have been reported. However, parents have abandoned chicks at colonies without documented mink predation, and chick starvation and poor fledging success have also been recorded, however most often in dry years.
Omfördelning av de skärgårdshäckande skrattmåsarna Larus ridibundus i Vänerns nordöstra del under perioden 1985—1995
Authors: Landgren Thomas
Published: March 2023

Since 1985, some forty islands and groups of islets in NE Vanern are censused yearly for breeding larids, waders, cormorants, etc. This paper reports on the population changes, colony occupancy and re-distribution of Black-headed Gulls Larus ridibundus in the census area during an 11-year period. The number of Black-headed Gulls is relatively modest, with a peak of 790 individuals in 1995. There has, however, been an interesting change in their distribution. Islands close to land have been abandoned and the gulls have settled on previously unoccupied islands and islets in the outer archipelago. The causes of this re-distribution are not known, but habitat changes (near-shore islands having become overgrown with tall vegetation) and predation by mink are suggested as two important causes.
Changes in numbers and habitat utilization of wintering Whooper Swans Cygnus cygnus in Sweden 1964—1977
Authors: Nilsson Leif
Published: March 2023

A country-wide survey of wintering Whooper Swans Cygnus cygnus was undertaken in south Sweden in January 1995 as part of an international census of the species. The paper reports on this census and analyses Whooper Swan counts from earlier International Waterfowl Census data to elucidate changes in numbers and habitat utilization of the swans. A marked increase in the number of Whooper Swans was found between the first country-wide surveys in the early 1970s and 1995, when the winter population was estimated to be at least 8,000. The increase is not reflected in the midwinter indices, calculated from the International Waterfowl Census data, due to an increasing tendency of the Whooper Swans to feed on land in the southernmost part of the country. In January 1995, nearly 60% of the Whooper Swans in Scania were found on fields, mainly rape and winter wheat, whereas in the other parts of the country the majority of swans still utilised water areas. Earlier in the season the Whooper Swans in Scania also used sugar beet spill for feeding. The field-feeding habit started in the 1970s.
The Nuthatch Sitta europaea population of Dalby Söderskog during 15 years: trend and fluctuations
Authors: Källander Hans
Published: March 2023

Nuthatches Sitta europaea were censused each spring 1977—91 in the 36 ha Dalby Söderskog national park, an old, mixed deciduous wood of oak Quercus robur, elm Ulmus glabra and beech Fagus sylvatica, situated less than 10 km ESE of Lund, southernmost Sweden. The number of territories varied between four and 21, that of pairs between four and 20, with one to three unpaired males defending territories in five of the years. The population size in spring co-varied positively with winter temperatures. Over the 15-year period, the population showed a statistically significant positive trend, increasing by c. 0.7 pairs or territories per year. Similar increases in Nuthatch populations have been reported from Poland, Denmark, Great Britain and Sweden during the same period, and in other Fennoscandian passerines during the last three or four decades, and may be associated with increasing mean winter temperatures.
Autumn migration of Blue Tit Parus caeruleus at Falsterbo, Sweden 1980–94: population changes, migration patterns and recovery analysis
Authors: Heldbjerg Henning , Karlsson Lennart
Published: March 2023

Extensive ringing data from Falsterbo, South Sweden, were used to analyse numbers, migration patterns and recoveries in the Blue Tit Pants caeruleus during 15 years (1980–94). The ringing totals as well as the totals from the migration counts at Falsterbo showed an overall increase of Blue Tits during this period. This corresponded with the trends from other monitoring projects in Sweden as well as the number of annually ringed nestlings. Analyses of the daily and seasonal migration patterns and the age and sex composition were carried out. The majority of the migrating Blue Tits were females, but with an increasing proportion of males with increasing numbers of migrating Blue Tits. The majority of the migrating Blue Tits were first-year birds and this proportion increased with the strength of migration. The results indicated that the same individuals may show repeated migration during several seasons, more like regular migrants than true irruptive species. The recovery analysis shows breeding area, migration routes and wintering areas for Blue Tits ringed or recaptured at Falsterbo. Obviously the major part of the birds originate from southern Sweden. They are short-distance migrants wintering in Denmark and northern Germany. Many Blue Tits also return inland when confronted with the sea at Falsterbo. The intensity of migration varied a lot from year to year. Strong migratory movements occurred more often towards the end of the study period and with increasing numbers of Blue Tits involved. It appeared that the key factors for the occurrence of strong migratory movements were a high population density, caused by high winter survival and good breeding results, in combination with a low amount of Beech mast or other food resources during the following autumn.
The wintering area of Shorelarks Eremophila alpestris breeding in Swedish Lapland
Authors: Svensson Sören
Published: March 2023

Although it is known that considerable numbers of Shorelarks winter in the North Sea region, it has also been suggested that Scandinavian Shorelarks winter in a southeasterly direction. There are only three previous recoveries of ringed birds, only one of them of a bird ringed in the breeding area which gave a doubtful recovery in Spain. Birds that were colour-ringed on the breeding grounds at Ammarnäs in southern Lapland have now given eight winter recoveries: one in southern Norway, six along the Swedish west coast, one in Jutland, and one on Jersey. A ninth recovery was made on the Varanger peninsula in August. This clearly shows for the first time that the Scandinavian Shorelarks winter in the North Sea region and not in any unknown area to the south-east.
Höststräcket av fisktärna Sterna hirundo och silvertärna S. paradisaea över södra Sverige
Authors: Johansson Björn , Jakobsson Gunnar
Published: March 2023

Simultaneous observations of migrating Common and Arctic Terns were carried out during afternoons and evenings for three years, 1990—1992, at eleven sites at the larger lakes in southern Sweden. The force and direction of wind seemed to be the most important factor determining the number of terns observed and the route they took when they passed mainland Sweden from the Baltic Sea. The principal direction of the migration was southwest, with a more westerly orientation for Arctic than for Common Tern. High numbers were recorded mainly in head winds, whereas the terns probably flew at high altitude in tail winds, when they were not observed from the ground. The orientation of the lakes in relation the migration direction also affected the counts by leading line effects. The terns often concentrated in the southern or southwestern parts of the lakes before they continued migration. Approximately 65,000—70,000 Common and Arctic Terns are estimated to pass the region in the autumn.
Sex differences in recovery pattern and migratory direction of Goldcrest Regulus regulus ringed in northern Europe during autumn migration
Authors: Grenmyr Urban
Published: March 2023

Among Goldcrests ringed in Denmark, Sweden and Finland, and recovered later the same autumn in the British Isles, a remarkably high proportion (30:5) of males are found , compared with the assumption of equal sex ratio or a surplus (55%) of males in the migrating population during autumn. Sex ratio bias was not found in birds ringed in Norway. Provided that males and females can be assumed to have on average the same relative fat deposits and that the sexes are morphologically similar, both sexes should have the same flight range. Differences in flight capacity can thus not be a main explanation to the sexual bias in the short time recoveries in the British Isles. An alternative explanation may be a difference in migratory strategy between the sexes when facing long sea passages. If there is a choice, e.g. an alternative migratory route along the coast, the females, although for unknown reasons, fly out over the sea to a lesser extent than the males. Different geographical situations, compared to the rest of southern Scandinavia, is assumed to explain why Goldcrests ringed in southern Norway and later recovered in the British Isles do not show the same sexual bias.
Smålommen Gavia stellata i sydvästra Sverige – beståndsutveckling och häckningsframgång
Authors: Eriksson Mats O G , Johansson Ingemar
Published: March 2023

The breeding population of Red-throated Diver in southwest Sweden has decreased with at least one third during a period of about 60 years, from the 1930's to the 1990's. The decline was most pronounced from the 1960's to the 1980's. After that, the decreasing trend levelled off, and there has been a slight tendency of recovery and establishment at new breeding sites, not previously used by Red-throated Divers. During 1980–96, the production was 0.67 "large" young per pair and year, which was considered to be sufficient to maintain a stable population size. There was a significant relationship between the average breeding success and the distance to fishing lakes. The tendency of recovery may be linked to improved conditions for foraging in freshwater lakes which have been limed in order to reduce adverse effects of acid deposition.
The influence of weather and food supply on condition and behaviour of juvenile Bluethroats Luscinia svecica in northern Sweden
Authors: Hansson Bengt
Published: March 2023

In this study, performed in a subalpine birch forest in northern Sweden, I examined the weight and fat status of juvenile Bluethroats Luscinia svecica in relation to the weather (measured as minimum temperature, precipitation and wind-force) and food supply (measured as number of insects). The results showed that the birds suffered weight losses during days with high wind-forces, probably caused by increased energy expenditure and decreased foraging activity during these days. Moreover, the number of insects, and hence the food supply, decreased after periods with rainfall and with progress of the season. These factors were, at least partly, the reason why the birds showed overall low fat scores and were unable to accumulate extra fat at the locality. However, individuals that left the area early in the season were relatively old and carried relatively large fat reserves. These birds probably performed a short-distance migration, and presumably had the advantage of reaching more favourable sites in terms of foraging conditions.
Östliga fiskmåsars Larus canus heinei uppträdande i Öresundsregionen
Authors: Bengtsson Kenneth , Pedersen Kjeld T
Published: March 2023

The common gull Larus canus occurs in the Western Palaearctic with two subspecies. L .c. canus breeds from Britain to western Russia where it is replaced by the slightly larger and darker L. c. heinei. The zone of contact is probably not distinctive and there is therefore a wide zone where birds with characters of both subspecies and intermediate individuals can be found. We have analysed ringing recoveries of birds ringed during the non-breeding season in southern Sweden and Denmark. We demonstrate that this area is frequently visited by birds which return to breeding grounds well into the geographical range of L. c. heinei. This is further supported by data on morphology showing that birds caught during winter are larger than the locally breeding birds. Observations of colour ringed individuals show that birds with a morphology suggesting heinei mainly occur between November and March, though a few, especially younger birds, have been sighted in the area around Oresund throughout the summer months.
Habitat distribution during the post-breeding and post-fledging period in the Reed Warbler Acrocephalus scirpaceus and Sedge Warbler A. schoenobaenus depends on food abundance
Authors: Chernetsov Nikita
Published: March 2023

Habitat selection in Reed and Sedge Warblers in late summer and autumn was studied on the basis of trapping in several sites along the Courish Spit. The study revealed that during the period of post-breeding and post-fledging movements birds, especially juveniles, were strongly associated with patches where their preferred food, plum aphids, was most abundant. Both Reed and Sedge Warblers were much more abundant in wet reed beds where more aphids were recorded, although many nests occurred in dry reed. The Reed Warbler re-distributed itself within reedbeds, whereas the Sedge Warbler moved into reed stands from breeding sites in nearby sedge and shrub, thus making a more significant shift in habitat selection between the breeding and post-breeding periods. The association of birds with concentrations of their prey suggests that the purpose of post-breeding and especially post-juvenile movements is to find sites which are most suitable for completing moult and pre-migratory fattening.
A dwarf Atlantic Puffin fledgling Fratercula arctica from Nólsoy, Faeroe Islands
Authors: Stempniewicz Lech
Published: March 2023

An unusually small Atlantic Puffin fledging Fratercula arctica was found on Nólsoy, Faeroe Islands, in August 1997. The bird was fully feathered with no down remnants and left the colony during the peak of the fledging period. Some of its measurements (those where feather length is crucial, such as wing and tail) fell within the range of minimal values found in young puffins fledging prematurely. Others, like bill and tarsus lengths with a prevailing skeletal component, were less than the lowest known values. Very small body size seems to account for the very low body mass of the bird. However, proportionally developed pectoral muscles as well as the bird's overall good appearance (fully feathered with no down) and behaviour indicated that it apparently was not food stressed or starving.
Fat reserves in Dunlins Calidris alpina during autumn migration through Gulf of Gdańsk
Authors: Meissner Włodzimierz
Published: March 2023

To describe fat reserves in adult and juvenile Dunlins during autumn migration in the Gulf of Gdańsk, multiple regression equations for estimating fat mass in Dunlins were derived. The average fat level in a particular wave of migrants depends on many factors. Low amount of accumulated fat suggests that this species migrates along the southern Baltic in small steps, similarly to the rest of Europe. The interpretation of the results is difficult because at least two distinct migration routes cross the Gulf of Gdańsk region. DunIins starting their primary moult had lower fat index than birds in advanced stages of moult. The rate of fattening in Dunlins depends on the quality of the feeding place (higher in the sewage farm than in the river estuary). Birds which stayed longer in the feeding area had, on average, lower fat mass increments than those leaving Gulf of Gdansk after a short stay. Birds with low fat mass started putting on weight immediately, whereas "fat" birds lost weight at the beginning. Those results confirmed Mascher's (1966) hypothesis about differences in body mass change rate during the first day of stay in birds with low and high fat reserves. The level of free fatty acids in the blood appears to be a factor controlling this pattern. Differences in fat accumulation between Ottenby (southern Sweden) and Gulf of Gdańsk are discussed.
Nest site selection of the White-backed Woodpecker Dendrocopos leucotos in the eastern part of Latvia
Authors: Krams Indrikis
Published: March 2023

The White-backed Woodpecker Dendrocopos leucotos shows decreasing population trends in most areas in Europe. The main reason for this is increasing activity of man in changing the species' habitat. My study on the distribution and breeding biology of the White-backed Woodpecker in the eastern part of Latvia provides some evidence that these local woodpeckers live in stable populations. In view of this, it is important to begin more serious studies on the Latvian White-backed Woodpeckers to develop successful protection programmes which could be useful also for the whole of northern Europe.
Field choice of staging Greylag Geese Anser anser in relation to changes in agriculture in South Sweden
Authors: Nilsson Leif , Persson Hakon
Published: March 2023

The Greylag Goose Anser anser has increased markedly in South Sweden in recent years. During 1985–1996 the field choice and local distribution of post-breeding foraging Greylag Geese was studied in an inland breeding area (with marked changes in land-use), and in a coastal area (with small changes in land-use) used by the same population. During late summer the geese gathered into one or two major flocks in the lake area and one or a few flocks in the coastal area. In the first years, geese in the inland area only made short feeding flights to crop fields close to the roosts, but with the introduction of large set-asides close to the roosts feeding flights were extended; the average distance increased threefold at two roosts and fivefold at a third. In the last year of the study, the fields close to the roost were again grown with cereals and the geese returned to their old pattern. The preferred feeding areas in the lake area were stubble fields and the geese started to leave the area when fields were ploughed. When available, peas were a preferred food before the harvest of cereals. In the first years of the set-aside programme, some set-asides were highly preferred early in the season. During the first years, relatively few geese used the coastal area, mainly in late autumn, but increased markedly in importance during the study period, whereas only a slight increase was found in the lake area. During the study period the Greylags in the coastal area established the new habit of feeding on sugar beet spill.
En jämförelse mellan fyra biotopers betydelse för fågelfaunan i mellersta Blekinge
Authors: Lithner Stefan
Published: March 2023

The birds were counted in four different habitats (coniferous forest, deciduous forest and two types of mixed farmland with much pasture and meadows, one near the coast and the other one upland) during winter (November 1997–March 1998) and spring (late April through June 1998) in the province of Blekinge, southern Sweden. One point count route with 12 points was established in each habitat. Five complete counts were made in each season with a five minutes count at each point. All birds seen or heard were counted, but in this study I included only birds that actually used (keeping a territory, feeding, resting) in the specific habitat of each route. The coniferous habitat was poorer than the deciduous one, especially in winter. Six of the 12 points in the coniferous habitat had no deciduous trees and it was mainly these monocultures that were poor. The other points with some deciduous trees compared well with the deciduous habitat. The two pasture habitats were much richer than the forest habitats in winter. In spring there was only a small difference between the forest habitats and the upland pasture habitat, whereas the coastal pasture habitat was much richer, mainly because of a few coastal species. Vicinity to lakes, watercourses and marshes was a key factor contributing to high species diversity in both farmland habitats.
Breeding birds of Race ponds in NE Slovenia and their trends during 13 years
Authors: Vogrin Milan
Published: March 2023

The breeding bird assemblage of the Rače fishpond complex in north-eastern Slovenia is described. There are three ponds (4.5 ha to 20 ha) which are managed for semi-intensive fish-farming. During 13 years (1986—1998), I estimated the number of breeding bird pairs on the bases of found nests and/or observed females with fledglings. Six species of non-Passeriformes, i.e. Tachybaptus ruficollis, Podiceps cristatus, Anas platyrhynchos, Aythya fuligula, Fulica atra and Gallinula chloropus, nested regularly. The total number of breeding pairs (excluding “possible“ breeders) varied between 12 in 1994 and 45 in 1998. During the period only two species declined, i.e. Anas platyrhynchos and Aythya fuligula. The numbers of two species pairs were positively correlated, i.e. Podiceps cristatus vs. Tachybaptus ruficollis, and Fulica atra vs. Gallinula chloropus. The densities among ponds were positively correlated in only one species pair, i.e. Podiceps cristatus and Gallinula chloropus. Although the total density was highest in the smallest pond, the difference among ponds was not significant.
Different migration strategies among Swedish Common Buzzards Buteo buteo revealed by the proportion of white birds
Authors: Kjellén Nils
Published: March 2023

Migrating Common Buzzards Buteo buteo were counted and aged at Falsterbo, Sweden in the autumns of 1990—1996. The study included a total of 48,000 individuals. Among these migrants, birds with a primarily white plumage were separated. Such birds form a significant proportion of the buzzards breeding in Scania, the southernmost Swedish province, but are very rare further north. The proportion of white buzzards at Falsterbo in autumn was also compared with the proportion among birds wintering in Scania. Using white buzzards as indicators of a southern population and comparing them with more normal/dark buzzards breeding further north in Sweden I demonstrate the following differences: (1) The southern population migrates earlier than normal/dark buzzards, adults as well as juveniles. (2) A larger proportion of juveniles than of adults migrates in the southern population. (3) Especially adults in the southern population are resident to a higher degree than more northerly breeders. Such a pattern of leap-frog migration among Swedish Common Buzzards is also supported by ringing recoveries.
Ökande antal övervintrande mellanskarvar Phalacrocorax carbo sinensis i Öresund
Authors: Bengtsson Kenneth
Published: March 2023

The Cormorant of the subspecies Phalacrocorax carbo sinensis has increased markedly in north-western Europe during the last decades. Most of the sinensis breeding in northern Europe migrate south in autumn with most birds wintering in the Mediterranean including the coast of North Africa. It has been known for a long time that birds from the Norwegian population of the subspecies carbo winter in coastal and offshore areas in southern Sweden, Denmark and the Baltic. During recent winters an increasing number of Cormorants have occurred in these waters and it is now believed that the increase has been caused partly by a change in the winter distribution of North European sinensis. In this paper I describe the increase in southern Öresund between Denmark and Scania. I also present data on winter recoveries from these and adjacent waters of sinensis birds ringed in Sweden. I suggest that the increase may depend on the abundance of herring or perhaps other shoaling fishes. I estimate that the large winter flock consume about 120 tons in December–January, which is 0.07% of the herring population in a peak year.
Male aggressiveness and the possible occurrence of group territoriality in the Brambling Fringilla montifringilla
Authors: Lõhmus Mare , Silverin Bengt
Published: March 2023

Bramblings are nomadic birds with an interesting breeding ecology. Their nests are often aggregated in groups of two to eight nests. Such aggregated nesting may indicate the existence of group territories, probably formed for anti-predatory purposes. The male Bramblings show much variation in colour pattern during the breeding season, with individuals ranging from completely black-hooded to virtually female-like grey-hooded. The colour pattern is probably age dependent, but may also be correlated with social status. The present study of breeding Bramblings was performed during the summer 1998 at Ammarnäs, County of Västerbotten, Sweden. We simulated an intrusion in the breeding territory, using an artificial intruder (a decoy) and a tape recorder with Brambling song, to find evidence for the group territory hypothesis and to investigate the possible correlation between male plumage pattern and aggressiveness. Only intermediate males (type 2) and black-hooded males (type 1) (i.e. no female-like males), were observed during experiments at 13 nests. The type 2 males were slightly more active and aggressive towards the intruder-decoy (an intermediate male), when tested close to the nest, than were the type 1 males. The decoy was never attacked by more than one male at a time, but there were more than one male present in 77% of the experiments, which does not exclude the possibility for the existence of a group territory.
Development of a dispenser toner dosing and its control algorith
Authors: Fursa O.O. , Titova O.V. , Losikhin D.A. , Vilshanskyi D.O. , Perekrestnyi Yu.S.
Published: March 2023

The object of the study is the toner dispenser. Due to the high demand for computer technology, there is a need for ancillary equipment that will meet the needs of today's world. Toner is a powder with a small particle size used in printing. Thanks to the mi-croparticles of this component, the printing industry has significantly improved the quality of the print. But with its dosage there are a number of problems. The general equipment for its dosing are dispensers. Dosage is a measurement of the required amount of product by weight, volume or piece. On a functional basis, toner dispensers are designed for accurate dosing from large containers to small ones. The dosing device must protect against toner dust or its emission. The measured amount of product is moved to the container or packaging material, and is called packaging. The range of required doses, compliance with the specified technological requirements during dosing, determines the use of dosing devices different in design and method of dosing. The paper analyzes and creates a working dosing device, screw type, they are used for dosing heavy products. It is difficult to ensure accurate dosing of products that are fluid and stick to-gether with little compression. The general technological parameters that must be con-trolled during the operation of the dispenser are weight, temperature and humidity. The operator who manages and monitors the technological process can change the load pro-gram, the amount of toner weight that is loaded into the container. During the opera-tion of the device, the air temperature must be monitored. After the end of the dosing cycle, the cleaning program is started by blowing the main components of the device with compressed air. The created dispenser allows to adequately describe the processes of controlled dosing movement and allows to investigate the dosing process in a contin-uous way. The algorithm is described and the structure of the automatic control system is developed, which provides the nominal load. A dispenser based on the ATmega328P microprocessor controller (IPC) based on the KEYSTUDIO UNO R3 board compatible with ARDUINO UNO REV3 is built. The ATmega16U2 microcontroller is used as a USB-UART interface, which allows to increase the data transfer rate. In this paper, thanks to a comprehensive approach to data analysis solved the problem of automating the pro-cess of dosing and analysis of methods of uniform loading.
COMBINED SYSTEM OF AUTONOMOUS CONTROL AND ORIENTATION OF MOVEMENT OF THE OBJECT IN 3D SPACE
Authors: Dymchenko A. , Klymenko S. , Kulyk О.
Published: March 2023

The paper presents an analysis of the developments of the "Rocketry Agency Student Rock-et" project and identifies the main research directions for the development of this project. Prospects for the development of a research student project are the task of developing sub-orbital rockets with a flight altitude of 80, 100 or more kilometers. Flights to such altitudes are impossible without the use of monitoring and control systems, so an essential and high-priority task is development of a flight monitoring and control system for suborbital rockets with taking into account the caliber of the D-150 and D-300 launch vehicles. The analysis of modern monitoring and control systems has been carried out, the advantages and disad-vantages of these systems have been determined. The most attractive for use for suborbital rockets with the given caliber are autonomous guidance and television guidance systems. It is determined that the use of such control systems is impossible, both in terms of the di-mensions of the design itself, and the price category of the system as a whole. A new com-bined system of autonomous control and orientation of movement of volume in space, which is built on a combination of capabilities of television, inertial and mechanical systems, has been developed. regarding the determination and maintenance of the main vertical of the flight path of a suborbital rocket with a given caliber of the D-150 and D-300 launch vehicles.
Fuzzy type-2 in the task of increasing the reliability of image segmentation
Authors: Akhmetshyna L.H. , Yehorov A.O.
Published: March 2023

To study the macro- and microstructure of alloys, enlarged images of specially prepared samples are used, which leads to increasing of the noise component and de-fects contribution. This requires the usage of image correction techniques to ensure the accuracy of photometry. This paper describes the possibilities of increasing the reliabil-ity of image segmentation and the clarity of identifying the boundaries of objects of in-terest through the usage at the stage of fuzzification the membership functions of type-2. The presented algorithm contains 3 steps. On the first step initial image is prepro-cessed in the next way: at first, the brightness of the initial image is decreased propor-tionally on the base of the power transformation usage; after that background restora-tion and alignment process is performed; after the end of this process the brightness of obtained image is increased proportionally on the base of the power transformation us-age. On the second step of the proposed algorithm the image obtained after prepro-cessing is interpreted as membership function of type-1 and membership function of type-2 is calculated on the base of this image taking into account its brightness charac-teristics. On the last step of the proposed in this paper algorithm the output image is formed on the base of the membership function of type-2. During calculating of the out-put image, we are performing its contrast enhancement. This paper proposes different ways of calculating membership function of type-2 and forming of the resulting image and compares the obtained results. The proposed method of adaptive calculation of the parameters of the transition to the type-2 space provides increased reliability and clari-ty of detection of object boundaries. Experimental results are given on the example of a real image of an electron microscope of an iron alloy sample and show the effectiveness of the proposed approach.
High-speed magnetolevitatve land transport with power supply by distributed photoelectric energy system with perspective energy storage
Authors: Dzenzerskyi V.O. , Plaksin S.V. , Pohorila L.M.
Published: March 2023

Among the various types of high-speed land transport a magnetic levitation transport (magnetoplanes) is recognized as the most promising, so research related to the improvement of this type of transport is relevant. The work is devoted to the integra-tion of three promising research technologies: magnetolevitative transport, photoelec-tric energy conversion and phase-metric radionavigation. It is this integration, i.e. the essential interpenetration of these three subsystems, results in an overall synergistic ef-fect. Achieving the goals of sustainable development of the national economic complex within the framework of traditional transport and energy technologies is problematic, as energy consumption of transport systems exceeds one third of energy consumption, and the fastest mode of transport – an air transport is one of the leading air pollutants. Therefore, the purpose of this work is to substantiate a promising way to solve this problem by combining in a single system of renewable energy technologies and magne-tolevitative transport. The methods of system analysis and decomposition, statistical analysis of solar insolation, radiophysical experiment, computer modeling of photovol-taic energy converters, algorithmization of current control processes and forecasting the energy storage devices state are involved. The result of the research is the development of physical and technical bases for the improvement of magnetolevitative transport. Conclusion: by combining in a single system of renewable energy technologies and mag-netic levitation transport it is possible to create a system of all-weather guaranteed power supply based on solar energy and a reliable precision high-speed control system in real time.
Adaptive tools for formation of the knowledge base of information and analytical system of training scientific staff
Authors: Rostoka M. L.
Published: March 2023

The author emphasizes the urgency of preserving the integrity of the scientific and educational process for the training of highly qualified personnel in higher education universities and research institutions. It is noted that the consequences of force majeure, including quarantine from the COVID-19 pandemic and the current martial law in Ukraine, cause some adjustments in the organization of training of scientific staff. In this regard, it is likely that the problem of creating a fundamentally new information-analytical system (IAS), which in this vector will include a specific knowledge base fol-lowing the requests of research users – subjects of scientific training. Thus, the article aims to present the results of the doctoral research, in particular on the intermediate content analysis of scientific, information and reference, educational and methodologi-cal and other literature sources and practice-oriented resources on the development of information technology and systems and their adaptive transfer, which will contribute to the accumulation of analytical information and its digitization. Emphasis is placed on the rationality of creation and use of intelligent IAS based on the formed specific knowledge bases using semantic technologies and ontological modelling. This is due to the existence of a large amount of diverse analytical information, based on which the issues of any research, which in the context of training is a mandatory component of sci-entific and educational activities of applicants for scientific education (undergraduates, graduate and doctoral researchers, etc.). It is claimed that a modern researcher will be able to master modern tools and expert technologies of information and analytical ac-tivities. A brief description of the adaptive tools with which the formation of a specific knowledge base in the IAS of training of scientific staff is presented. It is noted that se-mantic and ontological approaches are the most effective in this regard for building in-formation systems, in particular those related to the development of information-analytical competence of applicants for scientific education.