Ábrahám Levente: Biomonitoring a Dráva folyó magyarországi szakasza mentén 2000-2004 - Natura Somogyiensis 7. (Kaposvár, 2005)

Fenyősi, László: Studies of avian communities along river Drava, between 2000-2004 (Aves) - Madárközösségek vizsgálata a Dráva somogyi szakasza mentén, 2001-2004-ben

124 NATURA SOMOGYIENSIS Table 3.: Checklist of species nesting in the Vízvár sample area between 2000-2004 Acrocephalus palustris Aegithalos caudatus Coccothraustes coccothraustes Carduelis carduelis Carduelis chloris Certhia brachydactyla Certhia familiáris Columba palumbus Cucidus canorus Dendrocopos major Dendrocopos minor Dryocopus martins Emberiza citrinella Erithacus rubecula Ficedula albicollis Fringilla coelebs Garrulus glandarius Locus tella fluviatilis Locustella naevia Motacilla alba Muscicapa striata Oriolus oriolus Parus caeruleus Parus major Parus palustris Passer montanus Phylloscopus collybita Phylloscopus sibilatrix Phylloscopus trochilus Picus canus Prunella modularis Remiz pendidinus Serinus serinus Sitta europaea Streptopelia turtur Sturnus vulgaris Sylvia atricapilla Sylvia borin Sylvia communis Troglodytes troglodytes Turdus merula Turdus philomelos Table 4.: Results of the surveys done in the Vízvár sample area between 2000-2004 Year Number of species Number of nesting pairs Density (pairs/10 ha) 2000 25 136 34 2001 35 233 58.25 2002 34 216 54 2003 33 241 60.25 2004 32 254 63.5 The monitoring of shoal-nesters Gravel shoals of the Drava are potential habitats for nesting communities unique in the Carpathian Basin, the species of which - Actitis hypoleucos, Charadrius dubius, Sterna albifrons and Sterna hirundo - can reliably indicate changes in the status of these habitats with their presence or absence. Surveying the gravel shoals is extremely difficult, due to special state border regulations, accessibility, and the erratic and unpredictable water regimes. The monitoring of shoal nesters is done as follows: - Drava section between river kms 199-180 is a distinguished monitoring area (Fig. 3.), where a complete survey of shoal nesters (Actitis hypoleucos, Charadrius dubius, Sterna albifrons and Sterna hirundo) is done, with regular samplings - populations of the the colony-nesting Sterna species are walk-surveyed in the entire Croatioan-Hungarian section of river Drava between Őrtilos (236 river km) and Bolhó (180 river km) - for the more exact knowledge of Actitis hypoleucos and Charadrius dubius nesting populations, we also survey the Croatian river section between Örtilos (236 river km) and Bélavár (199 river km), and also make population estimations.