Waterbird and raptor counts at most important wetlands of the island of Pag

Abstract

From March 27th to 30th 2016, waterbirds and raptors were counted at six saltwater and freshwater wetlands of Pag Island. In total, 803 ha were closely examined and 50 waterbird and raptor species with 2,190 individuals counted within the area. A total of 17 hours and 40 minutes (Table 1) were spent for this purpose, with the average observation intensity of 1.3 minutes per hectare. The most abundant among them was the Yellow-legged Gull Larus michahellis with 1,118 individuals, followed by Wood Sandpiper Tringa glareola with 369 and Coot Fulica atra with 146 individuals. 21 breeding species were registered, their population sizes estimated and status given (Table 2). In comparison with the national population sizes (Tutiš et al. 2013), the following three species: Black-winged Stilt Himantopus himantopus (17-31%), Stone Curlew Burhinus oedicnemus (>5-7%) and Kentish Plover Charadrius alexandrinus (64%) form a significant share of the Croatian national population concentrated on Pag Island. Of special relevance are the breeding Lapwing Vanellus vanellus (the only nest-site of this species on the islands of the Eastern Adriatic) and Shelduck Tadorna tadorna (the first documented breeding in Croatia). On the other hand, the low number of species and the actual number of raptors is a cause for serious concern. The presence of sheep in the wetlands with the highest number and the greatest diversity of waterbirds (Table 1) was quite indicative. In the future, the greatest possible attention should be dedicated to sheep grazing in marshy habitats, in order to retain the character of these internationally unknown and therefore nationally underestimated insular rest areas for birds migrating along the Adriatic Flyway. It is implicit that the significance of Pag Island for waterbirds during their spring migration is thoroughly investigated on the basis of turnover

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