ORNITHOLOGICAL EVALUATION OF THE LOWER STREAM PART OF THE ALLUVIUM OFTHE RIVER MORAVA (SLOVAK-AUSTRIAN FRONTIER)

The lower part of the floodplain area of the Morava river at the Slova k-Austrian frontier was till 1990 closed for the public and from the o rnithological viewpoint it is most valuable part of the 107.5 river km long Slovak reach of the river. This parr of the alluvium (from the 0 km at the confluence of the Morava and the Danube up to the confluenc e of the Morava and Dyje) on the area of 9050.4 ha includes a complex of floodplain forests, dead arms, marshes, natural and semi-natural we t meadows being almost unknown in Slovakia. During our investigation i n the lower part of the alluvium we found 201 bird species, i.e. 92.62 % from the total amount of species found on the alluvium of the whole Slovak reach of the Morava river. 111 of them were nesting birds. Mos t species were found in floodplain forests (86) with the highest part of nesting birds (83.7 %), less on meadows (84), and dead arms and mar shes (82). A most conserved biotopes are on an interleveeal area (3527 ha). We can find here also a larger part (1672 ha) of the whole area (2329 ha) of wet meadows. From the ornithological viewpoint this bioto pe is one of the most endangered ones in Slovakia. Except from suitabl e nesting conditions for rare nesting birds it offers rich supply of f ood for bird populations on the left-side (Slovak) and right-side (Aus trian) areas of the alluvium. It is important mainly for birds of prey , white stork (Ciconia ciconia) and common heron (Ardea cinerea) nesti ng in colonies in the WWF reserve. A comparison of qualitative-quantit ative representation of birds on the monitoring plots in the floodplai n forests of the alluvium of the Morava, Danube and Little Danube refl ects the difference in species composition of vegetation in floodplain forests. Since 1993 the whole alluvium of the Morava has been a selec ted Slovak area protected by the Ramsar Convention.