Effect of reed burning and precipitation on the breeding success of Great Reed Warbler, Acrocephalus arundinaceus, on a mining pond

Authors: THOMAS OLIVER MÉRO, ANTUN ZULJEVIC, KATALIN VARGA, RENATA BOCZ, SZABOLCS LENGYEL

Abstract: In this study, we present the effects of reed burning and precipitation on the breeding success of Great Reed Warblers on a mining pond (2008-2011). Breeding success, i.e. the probability that an egg would produce a fledgling, was 0.43. Clutch survival was lowest in 2010, due to the precipitation and high water level during the season. Breeding success was higher in the second half of the breeding season, although in 2008 and 2011 precipitation was also higher in the second half than in the first half of the breeding season. During the first half of the breeding season, daily egg and nestling survival did not differ. However, in the second half of the breeding season, daily egg survival was higher than daily chick survival. In years when reed was burned, breeding density varied between 7.7 and 12.3 pairs ha^{-1}, which was not significantly lower than in years when reed was not managed (average: 13.2 pairs ha^{-1}). Despite the availability of fresh reed in large areas, birds placed their nests mainly in mixed reed stands. Breeding success in fresh and mixed reed did not differ. Generally, breeding success and density were not affected by reed burning, but water level affected breeding success and density.

Keywords: Daily survival rate, water level, breeding density, Mayfield's method, Kaplan-Meier survival curve, ecological trap

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