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Interim report of the HELCOM CORESET project

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<strong>of</strong> <strong>the</strong> real number <strong>of</strong> nestlings by 11% (Hauff & Wölfel 2002). Using this correction factor for <strong>the</strong> nests<br />

not climbed (about 50% <strong>of</strong> <strong>the</strong> total German sample), <strong>the</strong> corrected brood size for Mecklenburg-Western<br />

Pomerania is 1.56, which is still clearly on <strong>the</strong> low side compared to most coastal records from Sweden<br />

(Figures 2.11 and 2.12).<br />

Figure 2.12. Mean nestling brood size 1996-2004 on <strong>the</strong> Swedish Baltic coastline (15 km zone), counties<br />

indicated by letters, and in Mecklenburg-Western Pomerania, (German data corrected for nests checked<br />

from <strong>the</strong> ground). Sample sizes given in brackets. The reference level up to 1950 based on data from <strong>the</strong><br />

Swedish coast was 1.84, with 95% confi dence limits 1.64 - 2.04.<br />

Factors affecting <strong>the</strong> white-tailed sea eagle reproductive success<br />

Organic<br />

contaminants<br />

Abundance, distribution and condition <strong>of</strong><br />

<strong>the</strong> white-tailed sea eagle population<br />

Productivity<br />

Nestling brood size Breeding success<br />

Food<br />

availability<br />

Availability <strong>of</strong><br />

territories<br />

(e.g. nest sites)<br />

Nest<br />

disturbance<br />

Persecution<br />

Figure 2.13. The productivity <strong>of</strong> <strong>the</strong> white-tailed sea eagle is affected by several anthropogenic pressures<br />

acting through <strong>the</strong> nestling brood size (number <strong>of</strong> nestlings) and <strong>the</strong> breeding success (success in raising<br />

one nestling per pair).

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