Aantalsevolutie en gedrag van dakbroedende Zilvermeeuwen <i>Larus argentatus</i> en Kleine Mantelmeeuwen <i>Larus fuscus</i> in België

In 1998, the first roof-nesting Herring Gulls Larus argentatus for Belgium were recorded at Oostende (along the coast) following indications of breeding in earlier years. Since then, breeding numbers increased from 33 pairs in 1998 to 205 in 2001. This is about 12 % of the total Belgian breeding population. In 1999, also Lesser Blackbacked Gull Larus fuscus started breeding on rooftops (4 pairs), followed by a moderate increase in the next years (up to 8 pairs in 2001). Roof-nesting Herring Gulls showed a different breeding behaviour than groundnesting birds, e.g. a much longer bound between parents and young and a longer breeding season. The coming years, a further increase of roof-nesting gulls along the Belgian coast is expected