Acta Ornithologica - Abstract Vol 40 (2)
Contents of Acta Ornithologica Vol. 40, No 2, Winter 2005
Campos F.1, Corchero-Gutiérrez F.2, Hernández M. A.3, Rivas J. M.4, López-Fidalgo J.5 2005. Biometric differences among Dipper Cinclus cinclus populations in Spain. Acta Ornithol. 40: 87-94.
2Joan Baptista La Salle 30, E-17002 Girona, Spain
3Department of Zoology and Ecology, Faculty of Sciences, University of Navarre, E-31080 Pamplona, Spain
4Sierra Nevada Ringing Station, Alcazaba 17, E-18191 Pinos Genil, Granada. Spain
5Department of Statistics, Faculty of Sciences, Plaza de los Caídos s/n, University of Salamanca, E-37008 Salamanca, Spain
Abstract. The length of the tarsus and wing and the weight of the Dipper were measured in four mountainous ranges in Spain (Cantabrian Mountains, western Pyrenees, the Central Mountains and Sierra Nevada). Birds from the Sierra Nevada were the largest but there were no significant differences among the other three areas. In the north, the range of the C. c. cinclus and C. c. aquaticus subspecies overlapped. In the south there was only aquaticus and in the central mountains only cinclus. The biometrics of cinclus in the north and centre were similar but aquaticus was larger in the south than the north. It seems that Spanish populations are in opposition to the Bergmann's rule predictions. The residual index (RI) was calculated for the individuals from the regression of mass/tarsus length. RI was higher in males than females in the northern populations, but the same in the centre and south. According to this index, males (but not females) were heavier than the theoretical weight in the north and lighter in the centre and southern ranges. Some of the variations in the Spanish populations are also discussed.
Meissner W. 2005. Variation in timing of Siberian Knot Calidris c. canutus autumn migration in the Puck Bay region (southern Baltic). Acta Ornithol. 40: 95-102.
Abstract. The first stage of the Siberian Knot's autumn migration between its breeding grounds in Taimyr, Siberia and the W European tidal flats is still poorly understood, despite our expanding knowledge of this species. This paper analyses data (1988-1995) on the numbers of Knots and the timing of their migration in the Puck Bay region of the Baltic Sea (N Poland). The timing varied greatly between seasons. In the case of juveniles, shifts in the timing of breeding caused by weather conditions at the breeding grounds are the main reason for this variation. The timing of adult migration is linked to breeding success. In seasons with low breeding success both males and females leave the breeding grounds earlier, and the correlation between the mean date of adult migration and the number of juveniles is consistent with this phenology. The differences between the departure dates from the Taimyr breeding grounds provided by published sources and the dates of arrival at Puck Bay suggest that Knots cross the northern tundra regions very quickly (at least, the earliest birds to arrive do so). The numbers of juvenile Knots turning up on the Polish coast appear to depend not only on the lemming cycle in the breeding grounds, but also on other factors, like local weather conditions, which could influence the number of juveniles observed.
Nowakowski J. K.1*, Remisiewicz M.2, Keller M.3, Busse P.1, Rowiński P.3 2005. Synchronisation of the autumn mass migration of passerines: a case of Robins Erithacus rubecula. Acta Ornithol. 40: 103-116.
1Bird Migration Research Station, University of Gdańsk, Przebendowo 3, 84-210 Choczewo, POLAND
2Department of Vertebrate Ecology and Zoology, University of Gdańsk, Legionów 9, 80-441 Gdańsk, POLAND
3Department of Forest Protection and Ecology, Warsaw University of Agriculture, Nowoursynowska 159, 02-776 Warszawa, POLAND
Abstract. The pattern of autumn migration in the Robin was studied through an analysis of daily dynamics for the birds caught in the years 1984-1997 at five ringing stations (two on the Baltic coast and three in inland Poland). In a given year, migration dynamics were found to be distinctly similar at all stations. They showed conspicuous consistence (ą 2 days) in the dates with peak numbers. This could be explained by assuming that Robins take off at the same time across a large breeding ground, and arrive almost simultaneously at stopover sites located over extensive areas. Moreover, migration dynamics from year to year at a given station were also remarkably similar, though this phenomenon was more distinct at the inland stations than at the coastal ones. Day-to-day fluctuations in numbers were on an average the highest at the coastal station most exposed to variable weather, the lowest at the inland stations, and intermediate at the more 'sheltered' of the coastal station. The paper discusses the extent to which such results can reflect the influence of weather conditions on passage, or else a precise internal (physiological and genetic) mechanism responsible for the timing of migration.
Orłowski G. 2005. Factors affecting road mortality of the Barn Swallows Hirundo rustica in farmland. Acta Ornithol. 40: 117-126.
Abstract. 99 road-killed Barn Swallows were found during three years of studies on a 48.8 km road network in an intensively farmed landscape in SW Poland. Nearly 88% of all road-kills were recorded in built-up areas and on road sections in their vicinity. The average number of road-kills per 1 km of roads was over twenty times higher in built-up areas than in open agricultural landscape (6.74 vs 0.33 road-kills/1 km). This paper investigates the influence of environmental factors (lines of trees along roads, number of livestock, volume of traffic, number of inhabitants) on the level of Swallow mortality on the roads in question. During the breeding season the number of birds killed in built-up areas was related positively to the number of cattle reared, the overall number of livestock (including pigs) and the number of inhabitants. In the multiple regression model following stepwise forward selection, the number of cattle explained 41% of the variance in the size of the whole-year road mortality of Swallows in the built-up area. During the autumn migration period the length of tree-lined road sections in the built-up area had an significant influence on road-kill frequency, explaining 36% of the variance in mortality. Mortality was high on tree-lined sections of road in adverse weather conditions.
Tomiałojć L. 2005. Distribution, breeding density and nest sites of Hawfinches Coccothraustes coccothraustes in the primeval forest of Białowieża National Park. Acta Ornithol. 40: 127-138.
Abstract. Long-term observations (1991-2002) have shown that Hawfinches breed throughout the extensive Białowieża Forest; they are only slightly less numerous in the forest interior than at its edge. Population size, habitat and choice of nest site were studied in two plots in a species-optimal habitat (continuous old-growth oak-lime-hornbeam woodland). The true breeding density there was 4.0-8.4, reaching as much as 15.2 p/10 ha in some years, while according to the combined territory-mapping method for the same period it was, on average, 5.8 pairs/10 ha in oak-lime-hornbeam, 3.3 pairs/10 ha in riparian ash-alder, but less than 0.5 pairs/10 ha in mixed coniferous-deciduous or young deciduous stands (marginal habitats for this species). Among the most numerous elements in the Białowieża Forest bird community, Hawfinches hold small nesting territories, which are sometimes loosely grouped. Nests are built at an average height of 18.1 (7-34) m in the canopy trees. Hornbeams are the preferred species for nests in the oak-lime-hornbeam stands (also clumps of mistletoe (Viscum album) in the continental maple), black alders in the riparian woodland. Originally, the Hawfinch must have been a species of old, high forest. Its recent nesting elsewhere low in bushes or, preferably, along woodland edges may well be a secondarily acquired trait; it could also be due to bias. Hawfinch nests are more easily discovered in such localities.
Witt K.1, Mitschke A.2, Luniak M.3 2005. A comparison of common bird populations in Hamburg, Berlin and Warsaw. Acta Ornithol. 40: 139-146.
Abstract. The main sources of data for this paper are recent monographs of the avifauna of three large cities situated in the northern lowlands of Central Europe along an 850-km-long west-east line. Estimates of several species' breeding populations in these cities were used to calculate their densities in the total area of breeding habitat in each city used by the species in question. The relationship of the densities of several common species was compared. Of 39 species analysed, 18 showed specific higher densities in Hamburg, 4 in Warsaw and 2 in Berlin. A gradient of increasing density from Warsaw to Berlin and Hamburg (Western gradient) was found for 16 species: Columba palumbus, Troglodytes troglodytes, Prunella modularis, Turdus merula, T. philomelos, T. viscivorus, Sylvia atricapilla, Phylloscopus collybita, Ph. trochilus, Regulus regulus, R. ignicapillus, Garrulus glandarius, Parus cristatus, Certhia brachydactyla, Fringilla coelebs, Pyrrhula pyrrhula. An opposite (Eastern) gradient was found for only 3 species: Columba livia f. domestica, Oriolus oriolus and Passer domesticus. Suggested causes for most of the larger differences among the three cities in the densities of particular species are the variation in the richness of vegetation (higher in both German cities) and differences in the stage of synurbization (i.e. adaptation to the urban environment) of specific avian species. In a few cases, factors such as the geographic range of a species, the attitude of humans (in the case of the Feral Pigeon), and specific, slight variations in habitat are put forward to explain the differences found.
Wuczyński A. 2005. Habitat use and hunting behaviour of Buzzards Buteo buteo wintering in south-western Poland. Acta Ornithol. 40: 147-154.
Abstract. During seven winter seasons (1993/1994-1999/2000) 107 roadside counts (28 km each) in agricultural area of south-western Poland were conducted. From among 1526 Buzzards, 1293 were recorded in winter months (November-February) and 233 in March. Birds were non-randomly distributed on nine vegetation types met along the transect route. Permanent papilionaceous crops, along with cereal stubbles, margin habitats, meadows and maize stubbles were preferentially used, whereas bare tillage and winter cereals were avoided. In general, Buzzards preferred habitats of the least amount in the studied area and avoided those which dominated. These data support the idea of high importance of small landscape structures for the biodiversity protection in intensively used farmland. During winter months, most Buzzards (59.5%) were perched when first sighted, most often on trees and in the middle part of their height. The percent of birds sitting on the ground amounted to 34.7%. The smallest amount of individuals (5.8%) was observed flying (flap-sailing, hovering and soaring), however this activity significantly increased in March (up to 17.1%). The significance of various hunting methods for wintering Buzzards is discussed. Even though it is a typical perch hunting raptor, the method of hunting from the ground seems to be particularly suitable for the conditions of winter farmland: common scarcity of perches, poor and low vegetation, local and temporary prey concentrations.
Xirouchakis S. M.1, Mylonas M.2 2005. Selection of breeding cliffs by the Griffon Vulture Gyps fulvus in Crete (Greece). Acta Ornithol. 40: 155-161.
2Department of Biology, University of Crete, P.O. Box, 2208, Heraklion 71409, Crete, Greece
Abstract. A multivariate study was carried out in order to investigate the most influential habitat variables and related features in the selection of breeding cliffs by the Griffon Vulture in Crete. The species was found nesting in mid-altitude areas, close to stock-raising units, on high limestone cliffs, which were also well protected against the prevailing winds of the island. A principal components analysis, which explained 53% of the total variance of the variables examined, differentiated Griffon Vulture colonies in relation to their isolation from other colonies, accessibility to humans and proximity to food resources. In addition, a stepwise discriminant function analysis between breeding and random cliffs included the height of the cliff, its substratum, the altitude, and the distance to the stockbreeding unit in a model that successfully classified 97.1% of the nesting and 88.2% of the random cliffs. In comparison to continental regions the Griffon Vulture colonies in Crete were located on higher cliffs but at a lower altitude. This fact should be attributed to the species nesting on steep coastal cliffs close to the livestock's wintering areas.
Czechowski P., Zduniak P. 2005. Intraspecific brood parasitism in Barn Swallows Hirundo rustica nesting in bunkers. Acta Ornithol. 40: 162-164.
1Institute for Tourism & Recreation, State Higher Vocational School in Sulechów, Armii Krajowej 51, 66-100 Sulechów, POLAND
Abstract. During a four-year study of the breeding biology and ecology of an atypical population of Barn Swallows nesting in 13 abandoned post-war bomb shelters, the unexpected presence of foreign juveniles in active nests with nestlings was recorded on eight occasions. In five cases, single birds were noted, and in the other three, two foreign individuals were observed. The average age of the nestlings joined by foreign juveniles was 11.6 days (SE = 1.08, range 8-16), while the average age of the latter birds recorded with the nestlings was 23.2 ą 1.02 days (range 20-25). The mean distance between the hatching and parasitised nests was 0.9 ą 0.11 m (range 0.5-1.2). This unusual behaviour in swallows seems to be deliberate and is aimed at choosing a nest with nestlings in order to obtain extra food from experienced adult birds rather than an error caused by the darkness in the shelter.
Hahn I. 1,2*, Römer U.3, Schlatter R.4 2005. First description of nesting ecology of the endemic Grey-flanked Cinclodes Cinclodes oustaleti baeckstroemii from the Juan Fernández Islands, Chile. Acta Ornithol. 40: 165169.
1Department of Ecology, Catholic University of Chile, P.O. Box 114-D, Santiago, Chile
2Institute of Landscape Ecology, University of Münster, Robert-Koch-Str. 26, D-48149 Münster, Germany
3Faculty of Biology, University of Bielefeld, P.O. Box 100131, D-33501 Bielefeld, Germany
4Institute of Zoology, Faculty of Sciences, Austral University of Chile, P.O. Box 567, Valdivia, Chile
Abstract. The habitat and nest sites of an island-endemic, the Másafuera Grey-flanked Cinclodes, are described for the first time. The species breeds only in natural cavities in steep rock-walls and rocky slopes or ridges. The nest entrance diameter ranges from 5.5 to 20 cm, the nest chamber being placed within the rock so as to be invisible from the outside. The nest sites found solely on Alejandro Selkirk Island were located from a little above sea-level to the summit region, the preferred habitats being barren canyon bottoms with small streams, and humid alpine plateaus. Nesting extends from early December to late January, indicating a core breeding season from November to January. Fledgling numbers per clutch average about two.
Mitrus C., Soćko B. 2005. Polyterritoriality and the first record of polygyny in the Red-breasted Flycatcher Ficedula parva in a primeval forest. Acta Ornithol. 40: 170-172.
Abstract. Territoriality in Red-breasted Flycatchers Ficedula parva was studied in the Białowieża Forest of Eastern Poland during five consecutive breeding seasons (2000-2004). 99 males were individually marked, and evidence of polyterritoriality was found in 10% of them. The proportion of polyterritorial males varied from 0% (in 2003) to 13.6% (in 2001). The mean distance between the first and second territories was 278.0 m (ą 179.37, n = 10). The rate of polyterritoriality was not related to age class, as older males defended dual territories that were, on average, not more distantly separated than those of younger males; the differences were not significant. One case of polygyny was recorded. To our knowledge, this is the first evidence for polyteritoriality and polygyny in male Red-Breasted Flycatchers.
Acta Ornithologica - Abstract Vol 40 (1)
Contents of Acta Ornithologica Vol. 40, No 1, Summer 2005
Bai M.-L., Wichmann F., Mühlenberg M. 2005. Nest-site characteristics of hole-nesting birds in a primeval boreal forest of Mongolia. Acta Ornithol. 40: 1–14.
Abstract. Nest sites of nine common hole-nesting bird species were studied in the West Khentey Mountains, NE Mongolia. Among three excavators, the Great Spotted Woodpecker used more aspens, larger trees, and more living or intact dead trees than the Lesser Spotted Woodpecker or the Willow Tit. Among non-excavators, the Nuthatch used mainly old holes of the Great Spotted Woodpecker, and the Red-throated Flycatcher frequently used those of the Willow Tit. Thus, the nest site characters of these two species resembled those of the original excavators, and their nests were placed higher than those of other non-excavators. The Coal Tit and the Great Tit used mostly branch holes in living trees. With respect to nest site use, the Daurian Redstart behaved as a generalist while the Common Treecreeper specialized in long slits. Among the excavators, nest site selection may be governed by body size, territory size and their different abilities of excavation. The non-excavators were best differentiated by their preferred hole type, and their tree use and nest site characters were mainly a consequence of the location of such holes. Interspecific competition did not appear to be important in the nest site use of hole-nesting birds in the study area.
Key words: boreal primeval forest, hole-nesting birds, cavity nesters, nest-site selection
Orłowski G1., Siembieda J2. 2005. Skeletal injuries of passerines caused by collisions with cars. Acta Ornithol. 40: 15–19.
2Department and Clinic of Surgery, Faculty of Veterinary Medicine, Agricultural University of Wrocław, pl. Grunwaldzki 51, 50–366 Wrocław, Poland
Abstract. Radiographic examination of 36 birds (18 species) killed on roads revealed bone injuries in 17 (47%) cases. There were 30 different kinds of injuries to the skeletal system. In 29 cases these fractures concerned the long bones of the wings (n = 15) and the lower extremities (n = 14). One bird had a dislocated spinal column. Wing fractures affected the humerus (n = 6), radius (n = 6) and ulna (n = 3), while leg fractures of legs affected the femur (n = 5), tibiotarsus (n = 8) and tarsometatarsus (n = 1). No relationship was found between the body weight and the location and number of bone injuries. In our opinion, the nature and type of skeletal injuries suggest that they were not the direct cause of death.
Key words: road-kills, small passerines, avian injuries, bone fractures, radiological analysis
Polak M. 2005. Temporal pattern of vocal activity of the Water Rail Rallus aquaticus and the Little Crake Porzana parva in the breeding season. Acta Ornithol. 40: 21–26.
Abstract. In the Water Rail the patterns of the two main types of vocalization were quite different: the announcement call was uttered throughout the breeding season with two peaks, one in April and the other in early June, but the courtship call occurred only in the pre-laying period. The vocalization period of the Little Crake is short but intensive, peaking before the start of incubation. In general, Water Rails produced more vocalizations in the evening than in the morning. The vocal activity of the Little Crake peaked at dawn. In both species a peak in vocal output occurred shortly before sunrise and before sunset.
Key words: Water Rail, Rallus aquaticus, Little Crake, Porzana parva, vocal activity
Rutkowski R. 1, Niewęgłowski H. 2, Dziedzic R. 3, Kmieć M. 4, Goździewski J. 5 2005. Genetic variability of Polish population of the Capercaillie Tetrao urogallus. Acta Ornithol. 40: 27–34.
5Polish Hunting Association, 1 Maja 25, 16–400 Suwałki, POLAND
Abstract. The Capercaillie is one of the most seriously endangered bird species in Poland. It currently numbers around 650 individuals that live in four isolated populations (Lower Silesian Forest, Janów Lubelski Forest, Carpathians, Augustów Forest). This study investigated genetic variability based on the polymorphism of six microsatellite loci in the surviving Polish populations of the Capercaillie and compares the results with the analogous variability in two large, contiguous populations in Russia. The following parameters were estimated: mean number of alleles per locus, allelic richness, mean effective number of alleles per locus, heterozygosity in each of the populations investigated. Differentiation between pairs of populations was assessed using FST. The results show that despite some inevitable reduction in genetic variability, most of the Polish populations retained a substantial level of microsatellite polymorphism. Only in the population from Janów Lubelski Forest was there a significant reduction in variability, probably due to long isolation and the recent decline. That this population has long been isolated was also confirmed by the pronounced genetic differentiation from the other Polish populations. The Carpathian population of the Capercaillie was found to be genetically structured, and in the Lower Silesian Forest population heterozygosity was lower, possibly as a result of the lek mating system and also the dramatic reduction in numbers.
Skórka P.1, Wójcik J. D.2 2005. Population dynamics and social behavior of Mistle Thrush Turdus viscivorus during winter. Acta Ornithol. 41: 35–42.
Abstract. Density and behavior of the Mistle Thrush occurring in the Niepołomice Forest (southern Poland) and adjacent open areas were studied during the winters of 1996/1997, 1998/1999 and 2000/2001 (December–February). Mistle Thrush densities differed significantly between winters. Abundance of thrushes decreased with winter progression. Bird density and mistletoe clump density were positively correlated. Birds held territories or grouped in flocks. In the forest, flocks were observed only during the winter 1996/1997 when the largest density of birds was noted. Flock size decreased throughout winter, but, simultaneously, the number of territorial birds was stable. It suggests that at the end of the winter 1996/1997 some birds from flocks started to hold territories. Bird flocks were observed also in open areas and they preferred to feed in pastures. In the forest, every individual territory consisted of several clumps of mistletoe on a few trees standing close together. Birds defended mistletoe clumps against conspecifics and also other species (Pyrrhula pyrrhula, Turdus merula, Dendrocopos major). Aggressive encounter rate was positively correlated with bird density and negatively with winter progression (winter progression was correlated negatively with berry supply), but surprisingly was not correlated with mistletoe clump density and temperature. It is possible that during years with high berry supply, the density of birds may be so large, that defending fruits against many neighbors may be too costly and less profitable than feeding in flocks.
Key words: Mistle Thrush, Turdus viscivorus, aggressive behavior, flocking behavior, fruit defense, mistletoe, Niepołomice Forest
Volodin I. A.1,2, Volodina E. V.2, Klenova A. V.1, Filatova O. A.1 2005. Individual and sexual differences in calls of the monomorphic White-faced Whistling Duck Dendrocygna viduata. Acta Ornithol. 43–52.
Abstract. The White-faced Whistling Duck is a waterfowl species lacking any differences in ornamentation, coloration, size or behavior between the sexes. For distant communication, this species uses loud whistles. We analyzed 12 spectral parameters of 344 whistles from 23 captive adult ducks (14 males and 9 females). Discriminant analysis showed 94% correct assignment to an individual (N = 279 calls from 14 birds; 15–22 calls per bird). Separately for 8 males (162 calls) and for 6 females (117 calls), discriminant analysis showed 99% and 93% correct assignment to individuals respectively. Discriminant analysis for sex (N = 86; 3 calls from each of 14 males and 5 calls from each of 9 females) showed 100% correct assignment. Intersexual differences were governed by frequency parameters, the values of which were significantly higher in females than in males. Cluster analysis showed that differences between sexes were expressed significantly more strongly than the individual differences. The fact that the “acoustical keys” differed as regards the identification of individual birds or their sex may significantly enhance the reliability of acoustical recognition systems in the White-faced Whistling Duck. The data are discussed in the context of the biology of the White-faced Whistling Duck and significant intersexual differences in syringial and tracheal anatomy, which may be responsible for the sharp distinctions between the sexes in the calls of this species.
Key words: White-faced Whistling Duck, Dendrocygna viduata, vocalization, individual differences, sexual differences
Wesołowski T.1, Czeszczewik D.2, Rowiński P.3 2005. Effects of forest management on Three-toed Woodpecker Picoides tridactylus distribution in the Białowieża Forest (NE Poland): conservation implications. Acta Ornithol. 40: 53–60.
2Department of Zoology, University of Podlasie, Prusa 12, 08–110 Siedlce, Poland
3Department of Forest Protection and Ecology, Agricultural University, Nowoursynowska 159, 02–776 Warszawa, Poland
Abstract. Distribution of Three-toed Woodpeckers and that of dead wood were mapped in two fragments of the Białowieża National Park (BNP) differing in their management history — primeval (old-growth stands of natural origin, no human intervention) and logged (as the former but subject to 80 years of commercial forestry). Data were collected during the breeding seasons 1999–2001. In the end of April 2000, the whole BNP was systematically searched; playbacks of drumming were used to enhance detection of birds. Presence/absence of Three-toed Woodpeckers and of dead wood (standing and downed Norway spruces and snags of other trees) were recorded within each forest sub-compartments (ca. 28 ha). Data from censuses done in smaller plots in 1975–1999 showed that in the primeval forest the woodpeckers bred twice more frequently in swampy and coniferous forests than in the oak-hornbeam habitat. These preferred habitat types covered larger areas in the logged fragment than in the primeval part (66% vs. 41%). Yet despite this, Three-toed Woodpeckers were recorded there over twice less frequently (14% of 176 sub-compartments) than in the primeval (36% of 164 sub-compartments) part. These differences followed sharp contrasts in the dead wood availability; all but one sub-compartments in the primeval fragment contained some form of dead wood, whereas dead spruces were missing in almost 30% of sub-compartments in the logged part. This was the effect of continuous ”sanitary” logging, purposeful removal of dying and dead spruces from the Forest. To restore Three-toed Woodpecker habitats it is necessary to ban removal of dead spruces in the managed part of BNP. However, the BNP area is too small, to assure the long-term survival of the Białowieża Forest population. To achieve this, it is necessary to resign from removal of dying and dead spruces in the whole Polish part of the Białowieża Forest (600 km2). This would create breeding habitat for a maximum 260–320 pairs.
Key words: Three-toed Woodpecker, Picoides tridactylus, conservation of endangered species, primeval forest, dead wood, snags
Wysocki D. 2005. Nest site selection in the urban population of Blackbirds Turdus merula in Szczecin (NW Poland). Acta Ornithol. 40: 61–69.
Abstract. Nest site selection in the Blackbird was investigated in two urban parks in Szczecin from 1997 to 2003. The age structure of the tree stands, the area of shrub coverage and the number of predators (apart from squirrels) were similar in both parks. 95% of the nests discovered at the beginning of the breeding season were found again in June and July. Any increase in the heights of the nest sites in successive periods of the breeding season and any changes in the type of vegetation selected for nest construction were recorded. In April, Blackbirds most often used coniferous trees. At the start of the season, when deciduous plants began sprouting leaves, Blackbirds preferred those whose leaves appeared earlier. But later in the season, no difference was found between the numbers of nests in trees developing their crowns earlier or later. The shorter period of nest use in conifers is probably due to their selective penetration by corvids. The selective penetration of such trees by predators probably reduces the frequency of nest building in them between the first (pentads 1–3) and second (pentads 4–6) period of the breeding season, despite the fact that they provide better concealment for nests. The selection of nest sites by the Blackbirds in this study confirms both the predator-pressure and the nest-concealment hypotheses.
Key words: Blackbirds, Turdus merula, nest site selection, urban population, predation
Agostini N.1, Premuda G.1, Mellone U.1, Panuccio M.1, Logozzo D.2, Bassi E.3, Cocchi L.4 2005. Impact of wind and geography on orientation behaviour of adult Honey Buzzards Pernis apivorus during migration over water. Acta Ornithol. 40: 71–74.
2Via Carlo Alberto 4, 89046 Marina di Gioiosa Jonica, Italy
3Via Provinciale 69, 24022 Alzano Lombardo (BG), Italy
4Via Ruffini 12, 41010 Piumazzo (MO), Italy
Abstract. During autumn migration across the Central Mediterranean, adult Honey Buzzards cross the sea at its narrowest point, between western Sicily (southern Italy) and the Cap Bon peninsula (Tunisia). This study investigated the influence of prevailing winds and geography on the orientation behaviour of migrants during this sea crossing from observations over two islands, one on the northern side, the other on the southern side of the Channel of Sicily. The flock was taken as the sampling unit. Honey Buzzards reached the island of Marettimo, approx. 35 km off western Sicily and 130 km NE of the Cap Bon peninsula, regardless of the direction of the prevailing winds (NW and S). By contrast, Honey Buzzards passed via Pantelleria, about 110 km SW of western Sicily and 70 km ESE of the Cap Bon peninsula, mostly during NW winds. Birds reached Pantelleria from the NE and left the island flying WNW. They applied true navigational abilities in choosing the shorter crossing between Pantelleria and Tunisia and showing a curvilinear migration. Our results agree in part with the “optimal use of wind” hypothesis. In particular, wind, geography and navigational abilities seem to interact to shape the orientation behaviour of migrating Honey Buzzards, perhaps to minimize the risks of non-stop powered flight over the water.
Key words: Honey Buzzard, Pernis apivorus, migration, water crossing, orientation, geography, wind, navigation
Goszczyński J.1, Gryz J.2 Krauze D.2 2005. Fluctuations of a Common Buzzard Buteo buteo population in Central Poland. Acta Ornithol. 40: 75–78.
Abstract. Studies carried out in the vicinity of Rogów in central Poland showed a 47% rise in the population density of the Common Buzzard, inasmuch as the average number of breeding pairs in the study area of 105 km2 increased from 18.2 in the years 1982–1991 to 26.7 in the years 2001–2003. Furthermore, an upward trend was observed for each separately investigated forest complex. Possible mechanisms underpinning this increase in density are discussed.
Key words: Common Buzzard, Buteo buteo, population trends, density
Montalti D.1, Ferman L. M.1, Camperi A. R.1, Soave G. E.1, Arambarri A. M.2, Darrieu C. A.1 2005. Winter diet of Great Pampa-finches Embernagra platensis in Guaminí Lagoon, Argentina. Acta Ornithol. 40: 79–82.
2Department of Vegetal Morphology, Faculty of Agrarian and Forestry Sciences, National University of La Plata, Av. 60 y 119, 1900-La Plata, Argentina
Abstract. The diet of the Great Pampa-finch includes seeds rather than insects. Our objective was to study its diet during the winter season and, whenever possible, to record differences between the sexes in diet patterns. This species was studied at Guaminí Lagoon, Buenos Aires Province, Argentina. The stomach content of 38 adult birds was investigated. The analysis shows that the food eaten by E. platensis consisted of seeds (60%) (Chenopodiaceae, Asteraceae, Ciperaceae and Poaceae) and insects (39%) (Bellostomatidae, Dytiscidae, Curculionidae, Coccinelidae, Formicidae and Apidae). Males ate more insects and, overall, more items than females. These, in turn, consumed a greater amount of plants. Niche breadth values were 2.9 for males and 3.1 for females. The seeds encountered were those of plant species typically associated with the pampas.
Key words: Great Pampa-finch, Embernagra platensis, diet, differences between sexes, Argentina
Wuczyński A. 2005. The turnover of White Storks Ciconia ciconia on nests during spring migration. Acta Ornithol. 40: 83–95.
Abstract. It is widely accepted that the first White Storks to arrive at a nest remain there to breed. In contrast to this belief, the paper describes the replacement of at least three males and at least one female at one nest in SW Poland during the spring of 1994. The first pair occupied the nest for 5–8 days, the second pair for one day, and probably only the third pair remained at the nest to actually breed. Additional data on arrival patterns show that such replacements of non-breeding storks may occur much more frequently than was previously thought, especially in areas of intense migration. Consequently, the most common phenological observations (e.g. the arrival dates of the first and second White Storks) are not really useful for defining the timing of breeding. It is suggested that the beginning of nest occupancy be defined by the beginning of the permanent stay of the second partner, and not just by the date of the birds’ first appearance.
Key words: White Stork, Ciconia ciconia, birds, methods, migration, phenology
Acta Ornithologica - Abstract Vol 39 (1)
Antczak M.1, Hromada M.2, Grzybek J.3, Tryjanowski P.4 2004. Breeding biology of the Great Grey Shrike Lanius excubitor in W Poland. Acta Ornithol. 39: 9-14.
3Polish Society for the Nature Protection "Salamandra", Szamarzewskiego 11/6, 60-514 Poznań, POLAND
Abstract. A Great Grey Shrike population was studied in two large plots (220 km2 and 176 km2) in western Poland in 1999 - 2003. During the study period densities varied from 11.4 to 14.1 breeding pairs/100 km2 but numbers were stable. In all, 180 Great Grey Shrike nests were found - 114 (63.3%) in conifers, 66 (36.7%) in deciduous trees. This populations reproductive parameters were relatively high in comparison to those of other European populations: mean clutch size - 6.6, hatching success - 92.5%, mean brood size - 5.72, mean number of fledglings per pair - 4.1, mean number of fledged young per successful pair - 5.25. Eggs (mean 27.1 x 19.9 mm) were found to be larger than reported in the literature. Nesting success was similar in both study plots, but there was slight seasonal variability: 52.6% - 41.0% from 99 nesting attempts in the first plot, 43.7% - 42.1% from 37 nests in the second. Predation was the main cause of nest losses. Plastic string used as nesting material appeared to be the most important cause of partial failures: 13 (8.2%) of a total of 147 nestlings surviving to fledging perished as a result of becoming tangled up in it. Nestlings rarely starved. Nests in linear habitats suffered significantly higher breeding losses (78.6%, N = 28) than those in non-linear habitats (50%, N = 90). The high fitness values obtained from this population were probably due to traditional farming practices, the sparing use of pesticides and the good potential food base.
Czeszczewik D. 2004. Breeding success and timing of the Pied Flycatcher Ficedula hypoleuca nesting in natural holes and nest-boxes in the Białowieża Forest, Poland. Acta Ornithol. 39: 15-20.
De Kroon G. H. J. 2004. A comparison of two European breeding habitats of the Water Rail Rallus aquaticus. Acta Ornithol. 39: 21-27.
Abstract. The study was carried out in two sites fluvial mires (FM) in Netherlands, and at salt marshes (SM) and the borders of lagoons (BL) in Spain. All 58 nests were found in unmown and ungrazed vegetation. Carex species were dominant at the nesting sites in FM, but not Phragmites australis. Juncus maritimus was dominant in the SM and at BL. The plant communities at and around the nest sites of FM differed from those of SM+BL.
At nest height from the side the nest was mostly only poorly visible. Nests at nest height and eggs at observer eye level were invisible among dense clusters of Juncus maritimus tussocks. Visibility of eggs in reed stands mixed with Carex species and in Sparganium erectum stands was mostly poor and moderate respectively. This was in contrast to nests situated among Juncus maritimus stems. Here, at eye-level the eggs were very conspicuous. For the most part, an incubating Water Rail on the nest at eye-level was hardly visible in any of the various stands. The vegetation height of nest sites in SM and BL was considerably less than in FM owing to the absence of Phragmites australis. The water depth at the nest sites varied. The nest height in tussocks of Juncus maritimus was greater. The nest material corresponded to the plant species in the immediate vicinity of the nest.
Kosiński Z.1, Kempa M.2, Hybsz R.3. 2004. Accuracy and efficiency of different techniques for censusing territorial Middle Spotted Woodpeckers Dendrocopos medius. Acta Ornithol. 39: 29-34.
2Ludowa 28, 63-700 Krotoszyn, POLAND
3Bolewskiego 122, 63-700 Krotoszyn, POLAND
Abstract. The aim of the study was to test whether the methods using the playback technique produce accurate data of population size when compared to the standard mapping and nest-searching methods. The three-visit method with audio-stimulation was found to produce data of the same accuracy (100%, N = 11 territories) as the standard mapping method, but the nest-searching method and single-visit with audio-stimulation yielded slightly lower estimates, 91% and 82% respectively, in comparison to the previously mentioned methods. However, the three-visit method with audio-stimulation was 2.2 times less time consuming than the five visits which used the standard mapping method (9h vs 20h). The three-visit method with audio stimulation could be appropriate for assessing distribution and abundance, and also for monitoring purposes.
Kozulin A.1, Vergeichik L.1, Stepanovich Y.2 2004. Factors affecting fluctuations of the Aquatic Warbler Acrocephalus paludicola population of Byelarussian mires. Acta Ornithol. 39: 35-44.
2Institute of Botany, National Academy of Sciences of Byelarus', Academicheskaya str. 27, Minsk 220072, BYELARUS'
Abstract. Data on the density of Aquatic Warbler and plant associations in the marshes of the Sporovskiy reserve (Byelarus) were collected between 1996 and 2003. The species density changed yearly from 135 to 0 males per km2. The density and numbers of these birds are governed mainly by changes in the groundwater table caused by floods, droughts or fires. Aquatic Warblers breed successfully when the groundwater table coincides with the topsoil level; the optimal water table lies in the range from 12 cm above the soil to 5 cm below it. Between 1981 and 2002 successful first-clutch breeding occurred 11 times (47.8%); in only 4 years was second-clutch breeding successful (17.3%). First and second clutches both failed in 9 years (39%). The pattern of changes in the population size and data on the recovery of the population size following such unfavourable years indicates that the key factors governing the overall population size are not migration or wintering conditions, but rather the state of the breeding biotopes. Active management of fenland still in its natural state is therefore of paramount importance.
Krupa M. 2004. Food of the Willow Warbler Phylloscopus trochilus nestlings: differences related to the age of nestlings and sex of feeding parents. Acta Ornithol. 39: 45-51.
Abstract. The study was conducted in the Lake Karaś reserve (N Poland), where the density of Willow Warblers in osier and birch thickets reached 28.7-33.3 p/10 ha. Collar rings were used to collect the food brought to the nestlings. 487 food samples were collected from 26 nests, comprising 2573 food items. 167 of the samples were from females (652 individual food items), 95 from males (616 food items). The nestlings were fed mainly on Arthropoda (94.6%) and Mollusca (5.4%). The dominant food items were Diptera (29.8%), Homoptera (28.7%), Ephemeroptera (10.5%), Araneida (7.6%) and Trichoptera (6.5%). The composition of the dominant food items and the average mass of food deliveries changed markedly with nestling growth. The types of food brought by each sex also varied significantly. Males brought heavier portions of food consisting of larger numbers of lighter prey. However, the composition of these portions was not as diverse as those brought by females. This may be related to differences between males and females in their respective territories and foraging techniques.
Mitrus C., Soćko B. 2004. Natural nest sites of the Red-breasted Flycatcher Ficedula parva in a primeval forest. Acta Ornithol. 39: 53-57.
Abstract. 117 nests of Red-breasted Flycatchers in Białowieża primeval forest (NE Poland) are characterised. Most nests (79%) were built in Hornbeam Carpinus betulus and Lime Tilia cordata. Three types of nest sites were distinguished: chimney shaped (26.4%), half-cavities (46.4%), or shelves the nest is wedged under a piece of bark against the main trunk (27.3%). Most cavity entrances were exposed to the south. Compared to other species of secondary cavity nesters in Białowieża National Park, Red-breasted Flycatchers used cavities of a different shape, with a smaller bottom area, and at a relatively low height above the ground (>>= 4.9 ą 3.12 m). Nesting trees had a smaller diameter (>>= 31.2 ą 21.4 cm) and were more often dead (27%) than trees used by other secondary cavity nesting species. Only four nest sites were used in consecutive seasons.
Orłowski G. 2004. Abandoned cropland as habitat of the Whinchat Saxicola rubetra in SW Poland. Acta Ornithol. 39: 59-66.
Abstract. The study was carried out on 94 abandoned arable fields (0.1-83.5 ha) comprising a total area of 400 ha in the intensively farmed region of the Wrocław plain (54.8 km2, SW Poland). A total of 101 Whinchat territories were found in the study area, all of them in abandoned crop fields with a well-developed layer of dried perennials from the previous year (Tanacetum vulgare, Artemisia vulgaris, Solidago sp.). Whinchats occupied 56 (60%) of the 94 fields surveyed. The probability of a Whinchat occupying a particular field was closely related to its size: the probability of occupation was 50% in fields of about 1.8 ha, and rose to 100% in fields larger than 13 ha. Single males occupied thirty-eight territories (37.6%). The number of Whinchat territories per occupied abandoned field lay between 1 and 14. Thirty-three fields held only a single Whinchat territory. The density of Whinchat territories was negatively correlated with the size of an abandoned field. Single males inhabited the smallest fields.
Tomiałojć L. 2004. Accuracy of the mapping technique for a dense breeding population of the Hawfinch Coccothraustes coccothraustes in a deciduous forest. Acta Ornithol. 39: 67-74.
Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120 Kraków, POLAND
*address for correspondence
Abstract. The accuracy of the territory-mapping technique for estimating the abundance of densely breeding Hawfinches was tested in an old and unfragmented lime-oak-hornbeam forest in the Białowieża National Park, E Poland. Hawfinch numbers estimated from counts of the whole bird community carried out with the application of the standards of the improved mapping technique were compared with seven-year data on the birds true numbers, which are known from parallel intensive nest searches and persistent tracking of the movements of pairs. In a forest with a dense population of Hawfinches the mapping technique underestimated their numbers by 20% in years of moderate density and by 35% during high-density years. Even though the underestimation was negatively correlated with the true density of Hawfinches, the figures obtained by both methods reflected year-to-year changes in a similar way. An improvement in mapping data is achievable either by closer attention being paid to the species during standard visits (the best ones for surveying it), or post factum by the introduction of a correction factor into the mapping-technique figures.
Nadeem M. S.1, Asif M.1, Maan M. A.2. 2004. Estimation of the Punjab (Pakistan) wintering population of the Houbara Bustard Chlamydotis macqueenii. Acta Ornithol. 39: 75-78.
2 Punjab Wildlife Department, 2-Sandha Road, Lahore, Pakistan
Abstract. The study was carried out in 3 plots in the province of Punjab (Pakistan) in November 2001. The total population of the Houbara Bustard was estimated at about 4 746 birds with an overall density of 0.147 ą 0.006/km2. The number of birds in Rajanpur/Rojhan was estimated at 685, in Thal at 672 and in Cholistan at 3 389.
Dariusz Wysocki D.1, Walasz K2. 2004. Nest sharing by two Blackbird Turdus merula females. Acta Ornithol. 39: 79-81.
Abstract. Two cases of nest sharing by two Blackbird pairs each were recorded during a long-term urban study. In the first case, two females simultaneously incubated eggs in the same nest. The nestlings were later seen to be fed by the two pairs of adult birds. In the second case, a nest containing 4 eggs laid by one female was taken over by another, which, having chased the nest owner away, laid 5 eggs of her own. The likely cause of nest sharing in the first case was the loss of eggs at an early stage of laying by the second female. In the second case, nest sharing seems to have been caused by nest competition. The details of the parents and siblings of the females involved in the first case permits the conclusion that the absence of competition between the females (and even their co-operation in feeding the young) was not caused by their genetic affinity.
Zając T., Solarz W. 2004. Low incidence of polygyny revealed in a long-term study of the Sedge Warbler Acrocephalus schoenobaenus in the natural wetlands of S Poland. Acta ornithol. 39: 83-86.
Institute of Nature Conservation, Polish Academy of Sciences, Al. Mickiewicza 33, 31-120 Kraków, POLAND
Acta Ornithologica - Abstract Vol 39 (2)
Antonov A. 2004. Smaller Eastern Olivaceous Warbler Hippolais pallida elaeica nests suffer less predation than larger ones. Acta Ornithol. 39: 00–00.
Abstract. The “costs of predation” hypothesis predicts that larger nests are more likely to be predated than smaller ones. However, nest size has not been found to be related to predation probability within any species. This study evaluated the “costs of predation” hypothesis in the Olivaceous Warbler during 2001–2003 in northwestern Bulgaria. Successful nests were significantly smaller and denser than those that were predated. Nest size decreased significantly during the course of the breeding season and increased with nest height. The relationship between nest size and the likelihood of predation was still significant even when the effects of laying date and nest height were controlled. Nest size was negatively related to fledging success even when only successful nests were considered. This finding is contrary to the prediction of the “sexual display” hypothesis, which states that nest size is positively related to fledging success, and suggests that nest size may signal phenotypic quality through the ability in this species to build a small but compact nest. It seems that both natural selection and sexual selection have led to the evolution of small nests in the Olivaceous Warbler. This is the most likely reason why the difference in nest-size between predated and non-predated nests was apparent, even in unmanipulated settings.
Key words: Olivaceous Warbler, Hippolais pallida, nest size, breeding, nest predation, fledgling success
Bańbura J.1,2, Perret P.2, Blondel J.2, Thomas D. W.3, Cartan-Son M.2, Lambrechts M. M.2 2004. Effects of Protocalliphora parasites on nestling food composition in Corsican Blue Tits Parus caeruleus: consequences for nestling performance. Acta Ornithol. 39: 00–00.
2Centre d’Ecologie Fonctionnelle et Evolutive, CNRS, 1919 route de Mende, 34293 Montpellier, FRANCE
3Centre de Recherché en Biologie Forestière, Universite de Sherbrooke, Quebec, J1K 2R1 CANADA
Abstract. The influence of a parasite (larvae of Protocalliphora, Diptera: Calliphoridae) on an avian host (Blue Tit) was studied in 1994–1997 as part of a long-term research project on a population of Blue Tits inhabiting nest boxes on the island of Corsica. The Blue Tit broods were heavily infested with Protocalliphora larvae. The abundance of caterpillars as a key food type for the tits was monitored. A random sample of 16 nests was experimentally subjected to an anti-parasite heat treatment, which resulted in a marked decline in the numbers of Protocalliphora larvae. Untreated nests, with high numbers of parasites, were regarded as control nests. Under the anti-parasite treatment, Blue Tit nestlings were fed less frequently than the control nestlings (8 v. 11 food items per hour per nestling). Significant changes in the diet composition occurred, with parasite-free nestlings being consistently fed with fewer caterpillars. An average parasitised nestling was supplied by its parents with 2.6 caterpillars more than an average parasite-free chick. This suggests that in the highly parasitised control nests, the parent tits made an effort to compensate for the detrimental effects caused by Protocalliphora larvae. Feeding rate and food composition were shown to influence chick condition and survival in the nest. In spite of these facts, the nestlings in parasitised nests developed less rapidly and had lower survival rates than in the anti-parasitically heat-treated nests. The parasitic Protocalliphora larvae have a double effect on their avian host: they adversely affect nestling performance, and they compel adult tits to work harder in order to at least partially compensate for that influence.
Key words: Blue Tit, Parus caeruleus, ectoparasite, Protocalliphora, food composition, diet, parental care, compensation, nestling performance
Hetmański T. 2004. Timing of breeding in the Feral Pigeon Columba livia f. domestica in Słupsk (NW Poland). Acta Ornithol. 39: 00–00.
Abstract. The study was conducted from 1997–2001 in the city of Słupsk. Observations of individually marked birds were conducted from blinds located at city-centre sites where Feral Pigeons breed. The pigeons bred throughout the year, with peak broods in spring and summer. Different pairs timed their breeding such that the beginning of the season (from October to September of the next calendar year) overlapped the dates of completion (from April to December). 10% of pairs had already begun breeding in the autumn, while 86% did so between January and May. The remaining pairs (young ones, in particular) started breeding even later, mainly because of the lack of suitable nesting sites. The breeding period most often ended between August and October (75% of pairs), when the pigeons began their moult. 91% of the young birds joined the breeding population in their second calendar year of life. The remaining young birds had their first broods in the first or third calendar year of life. Pairs of young birds started nesting 2–3 months later than adult birds. The average length of a pair's breeding season was 183 days.
Key words: Feral Pigeon, Columba livia f. domestica, chronology, reproduction, structure of breeding population
Purger J. J.1, Mészáros L. A.1, Purger D.2 2004. Ground nesting in recultivated forest habitats — a study with artificial nests. Acta Ornithol. 39: 00–00.
2Natural History Department of Janus Pannonius Museum, Szabadság u. 2. H-7623 Pécs, HUNGARY
Abstract. The study was carried out in the outskirts of the town of Pécs (southern Hungary) in a recultivated former coal mine. Bordered by Turkey Oak forests, this open area forms a wedge-shaped clearing in that woodland. Since trees and taller shrubs are rare in the area, it is mainly ground nesting bird species that occur in the clearing. In order to discover whether it is more advantageous to nest in the recultivated area (clearing) than in the nearby forest or at its edges, 150 artificial ground nests were constructed. On 7 May 2002, one quail egg and a plasticine egg of similar size were placed in each of the artificial nests. After a week it was found that 24% of nests in the clearing, 30% of those in the forest edge, and 44% of the ones inside the forest had suffered depredation. The proportions of damaged plasticine and quail eggs inside the forest and at the forest edge were similar, whereas the quail eggs in the clearings were significantly less damaged than plasticine eggs. Of all the experimental eggs, significantly more plasticine eggs (29%) were damaged than quail eggs (17%), which suggests that small-bodied predators are unable to break the quail eggs. 18% of the plasticine eggs attacked, and 72% of the quail eggs attacked were removed from the nest by the predator. Among the predators, small mammals were dominant in the clearing and inside the forest, and birds at the forest edge. Based on the predation of quail eggs, the survival chances of ground nests in the clearing are greater than at the forest edge or inside the forest.
Key words: artificial ground nest, plasticine egg, quail egg, nest predation, recultivated area
Randler Ch. 2004. Aggressive interactions in Swan Geese Anser cygnoides and their hybrids. Acta Ornithol. 39: 00–00.
Abstract. Evidence for direct interspecific competition in wildfowl and between hybrids and their parent species is scarce. This study examined threat displays and agonistic encounters (n = 324) in a goose flock of 140 Swan Geese and 13 hybrids with Greylag Goose living in Heidelberg, SW Germany. In general, agonistic behaviour made up less than 1% of the time budget throughout the year as measured by focal animal sampling. Most encounters (84%) were won by the initiator, both in Swan Geese and in hybrids. No difference was found between Swan Geese and hybrids in the outcome of an encounter, suggesting equal competitive quality. There were differences with respect to threat postures with hybrids performing diagonal neck threats more often and intentional movements less often. This seems to be related to their hybrid origin, since Greylag Geese most often show diagonal neck and forward threat displays. There was no direct evidence for hybrid superiority or inferiority.
Key words: Swan Goose, Anser cygnoides, Greylag Goose, Anser anser, aggressive behaviour, foraging, hybrid superiority, competition, threat postures, wildfowl
Tworek S. 2004. Factors affecting temporal dynamics of avian assemblages in a heterogeneous landscape. Acta Ornithol. 39: 00–00.
Abstract. The influence of the characteristics of habitat fragments on the dynamics of avian communities and the effect that fragments of different sizes have on the stability of the breeding species composition, and also on local extinction, colonisation and turnover rates were studied in an agricultural landscape in southern Poland. The fragments included various habitat types that differed from the matrix. Breeding birds were surveyed using the territory mapping method to assess turnover. Species composition depended on both the spatial structure of a fragment and the features of its surroundings. Local declines and appearances of species had a similar influence on the turnover in all size classes of the fragments. Species that contributed most to the total turnover were: Lanius collurio, Phasianus colchicus, Anas platyrhynchos, Emberiza schoeniclus, Columba palumbus and Sylvia communis. However, there were differences among species contributing most to the turnover according to area size classes. Heterogeneous habitats in a mosaic-like, agricultural landscape do not function as islands. The existence of species in an area with such a level of habitat patchiness can be related primarily to habitat quality, mainly because of poor isolation and the high permeability of isolating habitats.
Key words: mosaic landscape, species composition, turnover rate, extinction, colonisation, species-area relationship
Zduniak P. 1,2, Yosef R.2 2004. Seasonal biometric differences between sex and age groups of the Graceful Warbler Prinia gracilis at Eilat, Israel. Acta Ornithol. 39: 00–00.
1International Birding & Research Centre in Eilat, P. O. Box 774, Eilat 88000 , ISRAEL
Abstract. An abundant resident in Israel, the Graceful Warbler breeds in the northern and central parts of the country and has recently invaded desert areas following their human settlement. Possible seasonal changes in age and sex structure were investigated, as were differences in body measurements in individual sex and age classes as well as changes in the numbers of the Graceful Warbler population in Eilat. No difference was recorded between spring and autumn in the proportion of males to females, nor were significant differences found in the numbers of males and females ringed during the spring and autumn seasons. There was a significant difference in the proportion of juvenile to adult birds trapped in spring and in autumn. Moreover, males had longer wings than females in both seasons. There were no differences in body mass or body condition between sexes in the two seasons. Furthermore, adults had longer wings than first-year birds. Juveniles had longer wings in autumn than in spring, but no differences were recorded in the adults in this respect. In addition, juveniles were in better condition in spring than in autumn; however, there was no difference in body condition of the adults between seasons. The fact that a significant trend was found in the numbers of Graceful Warblers trapped in spring but no such trend in autumn, that a large proportion of recaptured birds were noted in both seasons, and that a high number of individual birds were caught repeatedly during the study period, suggests the existence of a stable or increasing breeding population in Eilat all the year round. In addition, the Bird Sanctuary is like an oasis in the desert environs of Eilat. Hence, the lack of differences among the years in the proportions of males and females between the seasons suggests that it is mainly breeding pairs that occupy the area.
Key words: Graceful Warbler, Prinia gracilis, Eilat, biometric
Milne R. J.1, Poiani A.2, Coulson G.1, Auld R.3 2004. Faecal Escherichia coli and Chlamydophila psittaci in the Superb Lyrebird Menura novaehollandiae: host sex and age effects. Acta Ornithol. 39: 00–00.
1Department of Zoology, University of Melbourne, Victoria 3010, AUSTRALIA
2Faculty of Science, Technology and Engineering, La Trobe University, Mildura, Victoria 3502, AUSTRALIA
3Victorian Institute of Animal Science, Attwood, Victoria 3049, AUSTRALIA
Abstract. The Superb Lyrebird is a sexually dimorphic passerine that although is not considered endangered, it has been declining in population size since the 1940s due primarily to urban development. Recent reports suggest that lyrebirds may be threatened by chlamydial infection. We studied levels of faecal infection by two microparasites in lyrebirds: Chlamydophila psittaci and Escherichia coli in the Sherbrooke Forest, south-eastern Australia. Fresh faecal samples were obtained from 33 lyrebirds (15 adult females, 13 adult males and 5 juveniles) — estimated of 27.5% of the population, all of them tested negative to Ch. psittaci. E. coli prevalence was compared between adult males and females and no difference was found. This result is expected, for instance, if E. coli is sexually transmitted and lyrebirds are promiscuous. Trends for juveniles to be more parasitized than adults were detected, but they were statistically not significant. Behavioural analyses of video footage indicate that E. coli infected birds did not allocate more or less time to any of the activities considered than did non infected birds. This might suggest that E. coli infection in lyrebirds is relatively benign, and behavioural effects may thus be subtle. No significant differences were found in specific measurements of foraging behaviour but non infected birds tended to scratch more frequently than infected birds.
Key words: Superb Lyrebird, Menura novaehollandiae, pathogens, Escherichia coli, bacteria, Chlamydophila psittaci, Chlamydia
Ponton F.1, Elżanowski A.2, Castanet J.1, Chinsamy A.3, de Margerie E., de Ricqlès A.1, Cubo J.1,* 2004. Variation of the outer circumferential layer in the limb bones of birds. Acta Ornithol. 39: 00–00.
1P. & M. Curie University, FRE CNRS 2696, 2 Pl. Jussieu, Case 7077, 75005 Paris, France
2Institute of Zoology, University of Wrocław, Sienkiewicza 21, 50–335 Wrocław, Poland
3Zoology Department, University of Cape Town, Private Bag, Rondebosch 7700, South Africa
Abstract. The core of the limb bone cortex of mammals and birds is made of rapidly deposited, fibro-lamellar bone tissue (also present in non-avian theropods), which is usually surrounded by an avascular outer circumferential layer (OCL) of slowly deposited parallel-fibered bone. We present the first comparative allometric study of the relative OCL thickness (expressed as a fraction of the diaphyseal radius) in modern birds. Body size explains 79% of the OCL variation in thickness, which is inversely correlated with size, that is, shows negative allometry (slope -0.799). This may explain the apparent absence of OCL in the ratites. Since the OCL is deposited at the end of growth, we propose that its relative thickness probably correlates with the amount of slow, residual growth, which our results suggest to be on the average larger in small birds.
Key words: bone histology, postnatal growth, ossification, skeleton, periosteal bone, phylogenetically independent contrasts
Acta Ornithologica - Abstract Vol 38 (2)
Errritzoe J.1, Mazgajski T. D.2, Rejt Ł.2 2003. Bird casualties on European roads - a review. Acta Ornithol. 38: 77-93.
Abstract. Road traffic affects the natural environment in numerous ways. The most striking of these is the death of wild animals and birds as a result of collisions with moving vehicles. In this paper the available data on bird mortality on roads is reviewed. Estimates of annual mortality for some European countries (350 000 to 27 million birds), the monthly distribution of casualties, their distribution among sex and age classes, as well as the methods used in the study of this problem are presented. The species composition of birds killed in this way is compared for several countries. In western Europe sparrows and blackbirds are the species that most frequently die on the roads, but in Central and Eastern Europe not only sparrows but also corvids and barn swallows make up a high proportion of the victims. Analysis of the monthly distribution of casualties in 10 species shows this to differ between countries, probably because of the geographic variation of certain aspects of their biology (migration, breeding etc.). Several factors affecting the frequency of casualties are discussed, and some suggestions for the prevention of bird casualties are also given.
Key words: road casualties, road kills, learning abilities, sex ratio, road planning, conservation
Bai M.-L., Wichmann F., Mühlenberg M. 2003. The abundance of tree holes and their utilization by hole-nesting birds in a primeval boreal forest of Mongolia. Acta Ornithol. 38: 95-102.
Abstract. The natural tree holes and nest holes of hole-nesting birds were surveyed in four forest types in the west Khentii Mountains of NE Mongolia. The utilization patterns of species, size and condition of trees, as well as hole types, were investigated. The average density of tree holes in the study area approached 30 holes/ha, while that of hole-nesting birds was 2.4 nests/ha only. The riparian mixed forest had the greatest number of species and individuals of hole-nesting birds, while the spruce-fir forest had the lowest numbers. Excavating bird species preferred larger, deciduous trees, and snags. Non-excavators did not select holes according to tree species or size, but preferred holes in living trees and branch holes. In view of the low occupancy of holes among the four habitats, we suggest that the density of secondary hole-nesting birds is not limited by availability of holes in the study area.
Key words: boreal forest, tree holes, hole-nesting birds, nest-site selection, cavity nesters
Dinevich L., Matsyura A., Leshem Y. 2003. Temporal characteristics of night bird migration above Central Israel - a radar study. Acta Ornithol. 38: 103-110.
Abstract. The purpose of the research was to find a time frame for the beginning, duration of maximum intensity, and end of nocturnal bird migration. The research was carried out using photo registration on a radar screen during the spring and autumn seasons of 1999-2001. Examination of the average length of daylight at the beginning of migration and the onset of civil twilight yielded a high correlation factor for both spring and autumn. The results showed that, on average, nocturnal migration began at the onset of civil twilight, that is, half an hour after sunset. The time elapsing between the onset of migration and the maximum concentration of migratory birds averaged about 70 minutes in both spring and autumn. Nocturnal migration usually came to an end within the one and a half to two hours after sunrise. We ascertained the seasonal time shift for the onset of nocturnal migration corresponding to the seasonal time shift related to the approach of darkness. The average times of the beginning, maximum intensity and end of nocturnal migration were found to be related to photoperiodic factors.
Key words: bird migration, weather radar, time features
Jayson E. A.1, Mathew D. N.2 2003. Vertical stratification and its relation to foliage in tropical forest birds in Western Ghats (India). Acta Ornithol. 38: 111-116.
2Plot No. 1234, West End Colony, Mogapair, Padi P.O, Chennai - 600050, INDIA
Abstract. The study was carried out from May 1988 to April 1993 in two types of tropical forests: the tropical evergreen and moist deciduous. The vertical distribution of birds and foliage abundance was recorded by visual observation in seven height classes, using the line transect method. The vertical distribution of 94 bird species was recorded in evergreen forest, and of 90 in moist deciduous forest. Bird species richness and the numbers of birds were highest in the stratum from 1 to 5 m in both the evergreen forests (57 species) and the moist deciduous forests (68 species). The species richness indices of birds in the two types of forest did not display such a clear relationship. Foliage abundance was high up to a height of 30 m in the evergreen forests, whereas in moist deciduous forests, foliage was abundant only up to 20 m. A significant positive correlation was obtained between foliage abundance and species richness and also between the numbers of birds in both types of forests. No significant correlation was obtained between foliage abundance and the species diversity indices in the two types of vegetation.
Key words: vertical stratification of birds, tropical forest, Western Ghats, Kerala, India
Olinkiewicz A., Osiejuk T. S.* 2003. Effect of time of season and neighbours on singing activity in the Corn Bunting Miliaria calandra. Acta Ornithol. 38: 117-122.
Department of Animal Morphology, Institute of Environmental Biology, Adam Mickiewicz University, 29 Czerwca 1956/198, 61-485 Poznań, POLAND
Abstract. The seasonal pattern of singing activity was studied in the Poznań region, W Poland. Males sang from mid-March till late July with a song rate varying between 3.2 and 11.1 songs/min. Song activity peaked at the beginning of the breeding season, in late March and April. In following months males also sang at quite a high rate, but the probability of finding a singing male within the territory was lower. Males sang mainly from tree tops and power lines at a height between 8 and 10 m. Males with larger numbers of neighbours had a significantly lower mean song rate than those with a single neighbour. Most probably, males with more neighbours had to spend more time on more active and direct territorial defence, and/or listening to the song of other males. The pattern we found suggests that song is mainly used in territorial defence against rivals, and that it is used as a first line of defence. Nevertheless, this does not preclude its usefulness for attracting a mate.
Key words: Corn Bunting, Miliaria calandra, song rate, seasonal pattern, territoriality
Surmacki A.1, Stępniewski J.2, Zduniak P.1 2003. Repeatability of egg dimensions within the clutches of Bearded Tit Panurus biarmicus. Acta Ornithol. 38: 123-127.
2Mała Kościelna 9, 64-113 Osieczna, Poland
Abstract. The variation in size and shape of Bearded Tit eggs was investigated in the Wielkopolska Region of western Poland in 1988-1992 and 1997-2000. The mean clutch size was 5.47 (95% CL: 5.25-5.70, n = 99), and differed markedly from year to year. Coefficients of variations for the mean egg characteristics in a clutch ranged from 1.91 (breadth) to 4.90 (volume). No significant correlation between egg length and breadth was found. Repeatability estimates were 0.50, 0.48, 0.50, 0.47 for length, breadth, volume and elongation index, respectively. The results suggest a relatively low heritability of egg dimensions in the population studied.
Key words: Bearded Tit, Panurus biarmicus, egg size, clutch size, repeatability of egg dimensions, biometry
Vlachos Ch., Bakaloudis D., Chatzinikos E., Papadopoulos Th., Tsalagas D. 2003. Aerial hunting behaviour of the Lesser Kestrel Falco naumanni during the breeding season in Thessaly (Greece). Acta Ornithol. 38: 129-134.
Abstract. We studied the foraging behaviour of Lesser Kestrels in agricultural habitats during the breeding season of 2000. The birds spent more time hunting in flight than perched. During 398 min. of observed aerial hunting, they spent 23.7% hovering, 14.4% hanging, 14.0% flapping, 41.2% gliding, and 6.7% soaring. The time spent on each type of aerial hunting behaviour depended on factors like breeding stage, time of day, wind speed, number of strikes, number of successful strikes, and the time spent hunting. The strike rate was 0.38 per min., the capture rate 0.10 per min. The capture rate depended on the type of hunting behaviour preceding the attack and was highest after the birds had been hovering.
Key words: Lesser Kestrel, Falco naumanni, hunting methods, strike rate, capture rate
Winton B. R.1, Leslie D. M. Jr.2 2003. Nest sites and conservation of endangered Interior Least Terns Sterna antillarum athalassos on an alkaline flat in the south-central Great Plains (USA). Acta Ornithol. 38: 135-141.
Abstract. We monitored breeding ecology of endangered Interior Least Terns on a 5 095 ha alkaline flat in north-central Oklahoma, USA. After nest loss, Least Terns commonly re-nested and experienced 30% apparent nest success in 1995-1996 (n = 233 nests). Nest success and predation differed by location on the alkaline flat in 1995 and overall, but nest success and flooding did not differ by microhabitat type. Predation was highest at nests £ 5 cm from debris (driftwood/hay) in 1995. No differences in nesting success, flooding, or predation were observed comparing nests inside and outside electrified enclosures. Coyotes and Striped Skunks were confirmed nest predators, and Ring-billed Gulls were suspected nest predators. We identified one location on the alkaline flat of about 1 000 ha with consistently lower nest losses attributable to flooding and predation and the highest hatching success compared with other parts of the alkaline flat; it was typified by open ground and bisected by several creeks. Management activities that minimize flooding and predation in this area could further enhance nest success and theoretically increase overall productivity of this population of Least Terns. However, the efficacy of electrified enclosures and nest-site enhancements, as currently undertaken, is questionable because of considerable annual variation in use by and protection of Least Terns.
Key words: Interior Least Terns, Sterna antillarum athalassos, apparent nest success, flooding, nest losses, predator exclosures, Oklahoma
Zduniak P.1, Kuczyński L.2 2003. Breeding biology of the Hooded Crow Corvus corone cornix in Warta river valley (W Poland). Acta Ornithol. 38: 143-150.
Abstract. The study area (16 km2) in "Ujście Warty" National Park, W Poland - was the valley of a lowland river at its confluence with the River Odra, covered by a mosaic of grassy vegetation and willow scrub. 111 breeding attempts were recorded during 2000-2002. The mean nest density (3.2 nests/km2) was higher than that recorded by other authors in agricultural landscapes, but lower than in urban areas. The nest construction was adapted to fit young willow trees. The mean clutch size was similar to that recorded in other populations (4.43), but eggs were smaller (41.2 mm x 29.1 mm). The hatching success was lower (76%) in comparison with other studies, but the mean number of fledglings (2.15 per nest and 2.96 per nest in successful broods) was relatively high. The main reasons for losses were unhatched eggs, predators, starved nestlings and poor nest construction. We hypothesise that the smaller egg size and lower hatching success recorded in this population was due to unfavourable and unpredictable feeding conditions (floods) during the period of egg formation and egg laying. Later in the season, receding floodwaters laid bare areas suitable for foraging on invertebrates; waterfowl eggs also became readily available. As a result of good conditions during chick rearing, the overall reproductive output was relatively high in comparison with other populations.
Key words: Hooded Crow, Corvus corone cornix, breeding biology, breeding success, clutch size, egg size, "Ujście Warty" National Park
Alabrudzińska J., Kaliński A., Słomczyński R., Wawrzyniak J., Zieliński P., Bańbura J. 2003. Effects of nest characteristics on breeding success of Great Tits Parus major. Acta Ornithol. 38: 151-154.
Department of Experimental Zoology and Evolutionary Biology, University of Łódź, Banacha 12/16, 90-237 Łódź, POLAND
Abstract. In this study, nest characteristics (size and proportions of basic components) were not correlated with the timing of breeding. Clutch size was negatively correlated with total nest mass but positively correlated with the proportion of the mass of the lining in the total nest mass. Analyses of hatching and fledging success showed that the quantity and proportion of moss in the nest structure as well as the nest size influenced the performance of eggs and nestlings at the nest. We suggest that variation in nest size and composition may be due to several contradictory pressures associated with the need to keep the moisture and temperature in the nest relatively constant, to protect the brood from predation, and to control sanitary standards.
Key words: Great Tit, Parus major, nesting, nest size, hatching, fledging
Kopij G. 2003. Diet of Cattle Egret Bubulcus ibis chicks in an intensively managed farmland in South Africa. Acta Ornithol. 38: 155-157.
Abstract. The diet of chicks was investigated in an intensively managed farmland in South Africa, after a prolonged drought, during the second brood (February/March). In comparison with other African studies, a larger proportion of frogs (mainly juvenile Pyxicephalus adspersus frogs) and a smaller proportion of grasshoppers (locusts and crickets) was recorded. This may have been due partly to exceptionally low rainfall rather than to different habitat or geographical location. The large proportion of locusts and flies in the diet indicates that the Cattle Egret may play an important role in pest control.
Key words: Cattle Egret, Bubulcus ibis, food, South Africa