We studied the effects of water level in the Danube River on waterbird species abundance and species assemblages along 83 km from the border of Hungary and Slovakia. 651,622 birds of 62 species were ...counted between 1992 and 2009. The dominant species was Mallard
Anas platyrhynchos
contributing 436,198 individuals (66.9% of all observations). Throughout the year total numbers of individuals and species richness were negatively correlated with local water level registered on the same day throughout the year. Shannon diversity indices were generally positively correlated with water levels. During floods, dabbling ducks, especially the dominant
Anas platyrhynchos
, dispersed to peripheral waters, where they are less likely to be counted, and diving ducks (
Bucephala clangula, Aythya fuligula
and
Mergus
spp.) left the area entirely, because fast flowing, highly turbid waters reduced local feeding efficiency. Abundance of most waterbird species decreased with elevated water levels. High water levels remove distinctive microhabitats (gravel banks, paved riverbanks and shoals), and create unfavourable conditions of high water velocity and turbidity. Retention of high water levels as a result of damming of the Danube creates long-term conditions similar to natural flooding effects. In our opinion, further manipulation of Danube water levels is likely to reduce waterbird richness and abundance and should be subject to appropriate environmental impact assessment.
We investigated the spatial and temporal patterns of migration of Eurasian Woodcock (n=23,539 specimens) collected in Hungary during spring sampling (2010–2019) in the framework of the Woodcock Bag ...Monitoring. There were differences in the temporal course of the spring migration of the species between the western and eastern regions of Hungary. In the western Hungarian counties, migration started earlier in all cases, while in Borsod-Abaúj-Zemplén county the main migration period – i.e. the period between the 25% and 75% cumulative sampling thresholds – started on average one week later than in Somogy county. We investigated the influence of weather factors on the spatial and temporal pattern of migration, in addition to geographical causes, based on the distribution of Péczely’s macrosynoptic situations recorded the week before and after the migration peak. In years free of weather extremes, the migration period was characterised by neutral (80.0%) macrosynoptic situations, with unfavourable (9.5%) and favourable (10.5%) conditions occurring less frequently. In the years with weather anomalies (2013, 2016, 2018), unfavourable macrosynoptic situations (81.3%) determined the spring migration characteristics. Weather anomalies (macrosynoptic conditions with gale-force winds and heavy snowfall) affected the timing of spring migration, but regional differences were observed in all years regardless of weather conditions, suggesting that spring migration of Woodcock is phase-delayed in the southern Transdanubian and north-eastern regions of Hungary.
Agricultural intensification presents a major threat to European biodiversity. This generalisation is largely based on studies from western and northern Europe. Here it is shown that the development ...of agriculture in a post-socialist country (Hungary) was marked by sudden changes, e.g., a 10-fold increase of fertiliser consumption in the late 1960s as a result of decision-making in the socialist command economic structures, and similar decreases after the collapse of socialism in the 1990s. Hungarian populations of two characteristic farmland species, the brown hare (
Lepus europaeus) and grey partridge (
Perdix perdix) are analysed and their collapse over the past four decades is related to agricultural data on production from FAO statistics. This decline was found to be negatively correlated with most measures of agricultural intensification (cereal and milk yields, number of machinery), and positively with cattle density. Multiple regression analyses of intensification measures indicated a similar pattern, although cattle density was not included into the models. Interestingly, farmland diversity in the models was negative predictor of population sizes. The sudden changes in agriculture were not indicated in the population trends of the two species. Probably, the relationship between agricultural intensification and small game species decline may not be as simple as correlation analyses indicated.
Morphometric characteristics of Eurasian woodcock collected during spring hunting (March) in Hungary between 2010 and 2014 were investigated to evaluate the accuracy of methods for determining the ...sex of live birds. We analysed the size dimorphism of biometric traits by sex, age, and sex and age, with sex determination (n = 13,226) performed by destructive methods and age determination based on wing examination (n = 8,905). Using the minimal important differences (MID) method, we demonstrated that, during spring migration, adult females have significantly greater mass and bill length than juvenile females and adult males, as well as a significant difference in body length compared to juvenile females. No biologically relevant differences were demonstrated between the sexes or age classes for other morphometric parameters. Conditional inference trees were applied to test whether body size parameters could be used to separate the age and sex of individuals. Based on posterior probabilities (55.4%), we suggest that biometric parameters no longer provide a sufficiently reliable method to separate age classes during the spring migration. Separation of sexes showed the best results for adult birds, with bill length (85.4%) and body mass (85.2%) proving the best predictors. The inclusion of additional morphometric variables (tarsus, tail, body and wing length) in the model did not increase the reliability of sex segregation, confirming the results obtained using MID, i.e. that there is no statistically verifiable biologically relevant difference between adult male and female birds for these parameters. A methodological innovation in this study was using MIDs for comparisons to determine biological thresholds for differences, the procedure helping to exclude Type I errors and determine biological significance.
The Old Lake of Tata, an important wild goose roosting site in Central Europe, is unique in its location being in the middle of a city with a population of 24,000. Consequently, the site is subject ...to intensive human disturbances. Goose migration and wintering on the lake was studied for over 37 years (1984–2021). In addition to weather, hydrological, and feeding conditions, particular attention was focused on human influences (which were deemed generally disruptive, but also beneficial in some cases) that can induce significant changes in the population dynamics of the 30,000–50,000 wild geese from 13 species wintering here. Almost without exception, the largest observed changes in the abundance of wild geese roosting overnight on the Old Lake are due to anthropogenic effects. In the majority of cases, the most significant population changes are due to impacts associated with the operation and upkeep of the lake and the New Year’s Eve fireworks. As a result, the winter operation of the Old Lake has been regulated by the Wild Goose Preference Mode since 2011, and the City of Tata has banned the use of fireworks during the winter period since 2018. Consequently, the conditions for wild goose migration have improved significantly. However, the situation of the Old Lake is still quite fragile and more conservation measures are needed to protect it further.
The woodpecker family (Picidae) includes numerous species that vary in size and plumage colouration, but which share many easily recognisable external features. These birds possess pronounced ...anatomical adaptions that enable them to exploit arboreal habitats and live in niches that are inaccessible to most other birds. The aim of this study was to increase our knowledge on the relationships between skull shape, habitat preference, pecking abilities and foraging habits of 10 European woodpecker species. A geometric morphometric approach was used to analyse two-dimensional cranial landmarks. We used principal component (PC) analyses on those measurements that may be related to habitat preference and foraging habits. The PCs resulted in descriptions of the relative length and width of the bill, variation in its relative size, orientation of the nostrils variation in the elongation of the
the relative size and position of the palatine bone, length of the
, and the thickness of the mandible bone. The analysis showed and confirmed the presence of some cranial elements that are strongly associated with habitat preference, pecking behaviour and excavation abilities.
At the turn of the 19-20th centuries, the Great Bustard population of the Kisalföld (Little Hungarian Plain) numbered 4000 specimens. By 1990, only about 100 individuals remained in the Hungarian and ...Austrian territories. Of the many possible negative factors of current times, the greatest pressure on the Great Bustard population stems from unfavorable crop structures, extensive use of intensive agricultural technologies and predation. During the past decades, we have seen a shift in nesting place locations from natural-like habitats to agrar-type habitats. This change may be explained by the more favorable structure and microclimate of this latter habitat type paralleled with greater food source availability. In order to escape this ecological trap, we have to engage in active conflict resolution that provides protection the region's Bustard population.
For this very reason, the MOSON Project was founded in 1992 at the northern part of the Mosoni-Plain in the territory of Lajta-Hanság Co. Later, several Austrian regions joined the project. On these territories, out of the above mentioned 100 specimens, only 20 birds lived at the time. As the result of active habitat management of Great Bustards and coexisting small game species (mostly due to the influence of set-aside areas) as well as effective predator control (especially the Red Fox) resulted in an increase of the Great Bustard population. By the end of the 1990's, the population grew to 120-130 individuals which number was limited by the carrying capacity of this territory. Consequently, the species continued to reoccupy new regions in the Hungarian and Austrian territories. These days, the number of Great Bustards in these protected regions is estimated to be 400 individuals.
In 1998, the Mosoni-plain was given IBA (HU-001) status, and in 2004, the region was protected under the Natura 2000 EU nature conservation network.
Abstract We have pointed out 272 plant and 217 animal, altogether 489 taxa in the diet of Great Bustard on the basis of data received from 9 (10) countries for Otis tarda tarda (Portugal, Spain, ...United Kingdom, Germany, Austria, Slovakia, Hungary, Ukraine, Kazakhstan, former Soviet Union). Out of 272 plant taxa, 40 were classified as cultivated plants, 232 wild plants and weeds. From the latter, 43 taxa were monocotyledons and 189 were dicotyledons. Animal food is shared among Annelida (n = 3), Arthropoda (189) Mollusca (2) and Vertebrata (23) phyla. Arthropods are mostly represented with Insecta (181), Arachnoidea (3), Chilopoda (2), Diplopoda (2) and Crustacea (mostly Isopoda) (1) classes. The component of the diet is possibly not related to selection but to the change of the abundance and availability of food and the ever present demand for animal food needed for the organism. Owing to the high number of taxa known as food, Great Bustard is definitely a generalist species. Due to the wide spectrum of animal taxa and because of the ability to subsidize the inefficient quality of food with quantity, Great Bustards can be regarded as a species with positive adaptation ability. It can be explained with a wide plant and animal food spectrum that Great Bustards even in intensive agricultural habitats can find food with indispensable quantity and quality.
We estimated the size of 30 defined populations of geese wintering in the Western Palearctic (including five released or reintroduced populations of three species). Fourteen populations were ...accurately estimated from almost full count coverage or robust sampling and ten were well estimated based on more than 50% of their total being counted. An estimated 5.03 million geese wintered in January 2009, up on 3.10 million in January 1993. Only two populations numbered less than 10,000 birds (Scandinavian Lesser White-fronted Goose and Svalbard/Greenland Light-bellied Brent Goose, the former being critically small within restricted range). Eighteen populations numbered 10,000–100,000, eight 100,000–1,000,000 and the largest 1.2 million individuals. Of 21 populations with known longer term trends, 16 are showing significant exponential increases, 4 are stable and one declining. Amongst these same populations, five are declining since the 1990s. Long term declines in productivity were found in 7 out of 15 populations. Amongst most of the 11 populations for which data exist, there were no significant long-term trends in annual adult survival. Improved monitoring, including demographic, is required to retain populations in favorable conservation status.
Hungary has many areas of international importance for four goose species during migration and wintering. Monitoring of numbers started in November 1984 and has been carried out monthly in ...October–March since 1986/1987 at all important sites. The maximum count of Tundra Bean Goose has decreased from 100,000– 120,000 birds in the 1980s and 1990s to about 15,000 today. Twelve sites are still of international importance. The maxima of Greater White-fronted Goose were below c. 50,000 in the 1980s. After a peak count of more than 150,000 in 1991/1992, maxima of c. 100,000 or more have been recorded in several subsequent seasons. Twenty-one sites are of international importance. The Lesser White-fronted Goose has declined drastically and after the 1997/1998 winter it is no longer recorded every month, and maximum has exceeded 53 birds only twice. Despite the small numbers, five sites are still of international importance. The Greylag Goose increased considerably both as a breeding bird and winter visitor. Currently the wintering population has stabilized with maximum counts of 25,000–30,000 birds. Seventeen sites are of international importance.