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

FENYŐSI L.: STUDIES OF AVIAN COMMUNITIES 129 Table 9.: Survey of other riverbank sites, 2001-2004 Year Area Number of colonies Number of Riparia riparia nest hollows Number of Riparia riparia breeding pairs Number of Merops apiaster breeding pairs 2001 Drava 236-199 river km 3 2400 1440 0 Barcs-Viktorpuszta 1 700 420 1 Total 4 3100 1860 1 2002 Drava 236-199 river km 8 980 588 0 Barcs- Viktorpuszta 1 1160 696 3 Total 9 2140 1284 3 2003 Drava 236-199 river km 9 1190 714 0 Barcs-Viktorpuszta 1 1820 1092 1 Bélavár, Csíkos 1 35 21 7 Total 11 3045 1827 8 2004 Drava 236-199 river km 9 2390 1434 1 Barcs- Viktorpuszta 1 920 552 1 Bélavár, Csíkos 1 25 15 10 Total 11 3335 2001 12 As a summary of our investigations, we want to note the following: - there was a decreasing trend of populations in the monitoring area during the studied period - the entire Drava region - i.e. the Drava section between river kilometres 237-133, including the Viktorpuszta and Csíkos pits - is rather characterised with stability (Fig. 7.); yellow parts of the bars in Fig. 7. indicate population sizes of the monitoring-areas, whereas the green segments show populations of the other areas. - although for determining the number of nesting pairs we employed the method known from the literature (i.e. 60% of nest hollows are considered to be occupied breeding pairs according to SZÉP 1991), we assume that due to the fact that Drava embankFig. 7.: Riparia riparia populations in the Drava region between 2000-2004