Morava River as the important area for raptor populations – concentration areas.


The following article shows the concentration areas of raptors in the Morava- region in the years 2009 - 2013. The study area situated in the common Border Area of three central – European countries - Austria, Czech Republic and Slovakia is made by the inundation of Morava River. Significant part of the area is made of Natura 2000 sites “Záhorské Pomoravie” on the Slovak and “March – Thaya – Auen” on the Austrian side. This area is long-term in relatively huge interest of ornithologist. We analyzed observations collected mostly during the Cross Border Cooperation Projects “Conservation of Raptors and Owls Slovakia – Austria CORO-SKAT” and “Improvement of a cross-border regional nature management in the March-Thaya-Auen RAMSAR - SKAT" and other datasets, collected in 2011 – 2013. In the area, 12 raptor species (without owls) are breeding, from which 7 are the species with European importance (Anex 1 of the Bird directive) and we worked mostly with data of this 7 species. We created the heat map of the species density and abundance concentration as the main result of this papper (Fig. 1). 

Key words: 

Imperial Eagle, White-tailed Eagle, Saker Falcon, Red Kite, Black Kite, Marsh Harrier, Honey-Buzzard, Montagu´s Harrier, Saker, Breeding site, Natura 2000.  

Study area: 

The study area is situated in the common Border Area of three central – European countries: Austria, Czech Republic and Slovakia (Fig. 1). The central part is composed by the Morava River, which make the border between countries. This area, former Iron Curtain between Western and Eastern Europe is the part of the (Central) European Green Belt and its Continental and Pannonian biogeographical and climatic region (Frobel & Geidezis 2011). In Germany, the European Green Belt is the most important connection line between ecosystems and is 1400 km long. From the end of the World War Two it was the line of death, from early 90s, it is the line of life (Geidezis et al. 2002).  Austrian – Slovak border area with its lowland river system is one of most important corridors and centers of biodiversity in  Central Europe. The Green Belt between Austria and Slovakia is 91 km long (Kortelainen 2010), from that 69 km is made by the Morava River (before regulations it was 80 km, Zuna-Kratky & Kürthy 1999). Some populations of raptors concentrated here have national importance (e.g. Red kite for Slovakia). 

The Area of interest is made by the geomorphological parts Borská lowland (Borská nížina – SK), Chvojnická highland (Chvojnická pahorkatina – SK),  Dolnomoravský úval (SK) and Pannonic Lowland and Highland ( Pannonisches Tief- und Hügelland - AT). 

The geomorphological parts on the Slovak side are associated in the common used name “Záhorská lowland” and characterised by altitude 140 – 297 m. a. s. l. The most important landscape types are floodplain forests, meadows, pine or oak forest and agricultural land – in Natura 2000 areas mostly grasslands. The average rainfall is about 650 mm per year, average temperature till 9 °C (Encyklopedický ústav SAV 1978). 

The geomorphological parts on Austrian side have a Pannonian – subcontinental, dry and warm climatic conditions with moderate cold and snow arm winter. In the summer, dry periods are abundant. The average rainfall is from 450 to 700 mm. 

There are several protected areas in addition to Natura 2000 sites with different level of nature protection on national levels. For the area, one nature protection office is responsible on the Slovak side (Protected Landscape Area Záhorie Directory in Malacky). 

Important factor affecting ecosystems is strong flood dynamics of the river. Flood in the area is year to year normal and inundation is on some locations up to 2.5 km wide. Highest water in recorded in March, lowest in September. Characteristic for the inundation is high number of still water (most of them are old river arms) and periodic waters with rare biodiversity. About one third of the area is wooded with floodplain forests. Most important trees are Narrow-leafed Ash (Fraxinus angustifolia), English oak (Quercus robur), Willows (Salix sp.) and Poplars (Populus sp.). Characteristic elements of the landscape are meadows (Subcontinental floodplain meadows, Zuna-Kratky & Kürthy 1999). 

The area of interest has an area of 290 km2, from which 125 km2 is Austrian part and 165 km2 is Slovak part (Zuna-Kratky & Kürthy 1999). 

Material and Methods: 

Data were collected during the following census programmes: 

  • Monitoring of breeding sites and pairs of target species in the area
  • Monitoring of migration of raptors 
  • Monitoring of wintering of raptors (basic random monitoring, White-tailed Eagle monitoring)
  • Monitoring on the roosting sites (Hen Harrier and Red Kite)

There are long term monitoring programmes of some species in the area – Saker Falcon, Red Kite, Black Kite, Imperial Eagle, White-tailed Eagle. For this species the data can be considered to be representative. For the rest of the species there are no long term monitoring programmes and data are collected randomly. 

Data used and discussed in the article are from the years 2009 – 2013, involving five breeding seasons. In the monitoring programmes, there is no special interest to prefer NATURA2000 areas, though the professional ornithologists are time-to time specialized on though areas. 

Monitoring of breeding sites and pairs of target species in the area and monitoring of breeding success. 

This programme was realised in 2011 – 2013 on both Slovak and Austrian side of Morava River. It consists of targeted and randomly chosen woodlands and other localities to detect the territories and found the nests. 

Monitoring of migration of raptors

Although the data from this programme are processed separately, for this study this data are used as well. Two transects on the Slovak side of the Morava river were chosen. Every month once each transect was visited. All observed raptors were recorded and these records were used for identifying of breeding pairs or breeding places. 

Monitoring of wintering raptors

There are two monitoring programmes in which we collected the data from the area: 1.) random monitoring outside of the breeding season and 2.) Regular monitoring of White-tailed Eagle on transects. 

Monitoring on roosting sites 

There is regular monitoring on selected roosting sites of Hen Harrier and, once a year in January made monitoring of Red Kite. 

Results and discussion: 

Red Kite Milvus milvus

From 24 identified breeding pairs, the nest site of 14 pairs is situated in NATURA2000 areas and the home range of other 7 pairs is situated in NATURA2000 areas. Most of them are in the floodplain forests near Morava river. With other 7 breeding pairs where more than 30% of total area of home range is situated in NATURA 2000 areas, NATURA 2000 areas has a key importance for survival of the species in the three countries region. During the autumn and winter, communal roosting in groups (5-40 birds)is typical for the Red Kite. For breeding and wintering birds food resources - dumps, meadows and wetlands are important. 

Black Kite Milvus migrans

In the border area it is a migratory species, only few individuals stays in the area during the winter. In 2012-2013, 8-13 pairs with the nest were known. The number of breeding pairs is certainly higher, especially on the slovak site. Only 2-4 nests are known on the Slovak site, all except one were recorded along Morava river. For breeding pairs, hunting areas with food resources - around water areas, on the meadows and on the dumps are important. Typically areas visited by black kites are dump near Zohor, wetlands near Malé Leváre as well as the Moravský Svätý Ján surroundings. 

Marsh Harrier Circus aeruginosus

It is regularly breeding species in the wetlands with reeds and high grasses. Occasionally pairs build nests in the arable land - in the wheat or rape fields. Number of breeding pairs is in a relationship to water level in wetlands. So, the population in the border area is changing between years. Whole population in the border area is estimated on 20-40 pairs. In the Slovak part, 24 (year 2012) and 26 (2013) breeding pairs were recorded. From this population, in the SPA Záhorské Pomoravie 18 breeding pairs were localized. Most stable local populations are on the lakes and ponds - especially Jakubovské rybníky ponds. Marsh harriers fly over long distance for food, regularly more than 10 km. Hunting areas represents meadows, fields and wetlands. 

Honey-Buzzard Pernis apivorus

In the area it is a regular but not common breeding species. Floodplain forests and also pine forests are typical nesting habitats. Number of breeding pairs is unknown because pairs frequently change the nests. Based on the observations of individuals and nesting territories, the population is estimated on 15-25 pairs in the area.  

Montagu´s Harrier Circus pygargus

It is a very rare species in the area, especially on the Slovak site. However the area is important for migrating birds during spring and autumn. The migration peak is in April and September. Whole population is estimated on 0-2 breeding pairs. Potential breeding habitat are wetlands, meadows and arable land with wheat or rape. Primary threat is the nest destruction by the agricultural work. Also water level in wetlands is important for successful nesting. From the border area are records of roosting places localized near the nest locations (Devínske jazero area, Borský Svätý Jur). 

Saker Falco cherrug

The population of saker falcon in the border area is located predominantly on the high-voltage pylons. Number of pairs is estimated on 5-10 pairs. From the Slovak part there is observed a decline or the move of pairs to Austria, where high quality hunting areas for falcons are present. 

Imperial Eagle Aquila heliaca

Whole population in the border area of Austria and Slovakia is estimated on 6-8 pairs. Only one pair is regular nesting on Slovak site. The area in Austria is rich in prey, so represents high quality hunting area. Some pairs regular change their nests each season, the nest can be remote several kilometers from the previous nest. The area along Morava river is important for immature eagles. Especially localities near villages Bernhardsthal and Moravský Svätý Ján represents temporary settlement areas for eagles. During autumn and winter, groups of 3-10 birds were observed on the fields and meadows.  

White-Tailed Eagle Haliaeetus albicilla

The population of white-tailed eagle is stable or increasing. Typical habitats are forests near water areas. 4-6 pairs are breeding in the border area. The nesting is often unsuccessful because of the human disturbance during the nesting season. The area is also important for immature eagles which creates a groups (3-10 birds) in some localities. Frequently eagles were recorded in two areas - north of Malé Leváre village and south of Vysoká pri Morave village, once speaking about the Slovak side. 

The area is rich on raptor species, in compare to other parts of both countries. For the identification of most important areas in the border area we analysed the density of raptor nests (imperial eagle, white-tailed eagle, black kite, red kite, marsh harrier, eagle owl, honey buzzard and saker falcon, see map). There are two most important localities for raptors in the floodplain forests near Hohenau an der March village and Marchegg village. These localities are surrounded by meadows (Slovak site) and arable land (Austrian site). Less important areas were identified near Devínske alúvium Moravy (protected area), Jakubovské rybníky ponds, Gajary village and Bernhardsthal village. For these areas the occurrence of wetlands and meadows is typical. Both habitat types are visited by raptors during migration and winter. Morava river and the area along the river is a Ramsar site and NATURA 2000 area, most important habitats are wetlands, meadows and floodplain forests. In the future, conservation of habitats should be primary aimed on the water level stabilization. Regular floodings protect the forest against human disturbance early spring. Also wetlands near the river are dependent on the flooding, especially marsh harriers need sufficient water level in wetlands for the nesting. 


Encyklopedický ústav SAV  (Veľký J ed.) 1978 A: Encyklopédia Slovenska, II. Zväzok E - J [The Encyclopedia of Slovakia, II. Volume E - J]. Veda, Bratislava, 531. [In Slovak]

Encyklopedický ústav SAV (Vladár J ed.) 1982 B: Encyklopédia Slovenska, VI. Zväzok T - Ž [The Encyclopedia of Slovakia, VI. Volume T – Ž]. Veda, Bratislava, 774. [In Slovak]

Frobel K, Geidezis L 2011: European Green Belt. From Iron Courtain to pan-European Lifeline. Committee on Environmental, Public Health and Food Safety, European Parliament Brussels. 

Geidezis L, Schlumprecht H, Frobel K 2002: Das Grüne Band. Ein Handlungsleitfaden. Bund für Umwelt und Naturschutz Deutschland. 

Kortelainen J 2010: The European Green Belt: Generating Environmental Governance – Reshaping Border Areas. Quaestiones Geographicae 29(4). 27 – 40. 

Zuna-Kratky T, Kürthy A 1999: Mehrjährige Greifvogelerhebung in den unteren March-Thaya Auen in österreichisch-slowakischen Grenzgebiet. Egretta 42. 17-29. 

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