Consultez les articles du Bulletin Aves !
Aves, 28/4 | 1991 | 169-188
Exceptionally high breeding figures for the Long-eared Owl (Asio otus) and the Kestrel (Falco tinnunculus) in 1991 in the Forêt de Soignes (Belgium).
De Wavrin, H., Walravens, M. & Rabosee, D.
In 1991, exceptional high numbers of Long-eared Owl and Kestrel bred in the Forêt de Soignes, an extensive beech forest to the south-east of Brussels. Taking into account only the Brussels region's part of this forest, 65 Long-eared Owl pairs (density: 3.92/km2) and 18 to 21 Kestrel pairs (density: 1.09 to 1.27/km2) were recorded. Extrapolation to the whole state forest (43.8 km2), the figures are respectively 172 and 48-56 breeding pairs. A similar phenomenon occured in 1971 and 1977 but to a lesser extend. These birds'habitat normally consists of semi-open countryside but on this occasion there was a marqued preference for the heart of the beech forest. Some pairs of Long-eared Owls nested also in neighbouring gardens. The main food source for these owls was Wood Mice instead of the usual Voles; that for the Kestrel was the Bank Vole. This unusual abundance in a forest was linked to a rodent population boom, itself the result of a heavy beech mast harvest in 1990, followed by a dry Spring in 1991. Concerning the Long-eared Owl, this exceptional abundance was seemingly also due to high over-wintering or post-wintering numbers, some birds remaining further to nest, as well in the agricultural areas of Brabant, as in the Forêt de Soignes itself.
Articles published in the same bulletin
Avifauna along artificiel spruce (Picea abies) succession at the Plateau des Tailles (Southern Belgium).
Deceuninck, B. & Baguette, M.
Loly, P. & Jacob, J.-P.
Detaille, R. & Daulne, J.-M.
Dufourny, H. & Lebailly, J.-L.
Clotuche, E. & Schaeken, P.
Fouarge, A.-M. & Fouarge, J.-P.
De Wavrin, H.
Van Der Elst, D., Lemaigre, F. & Schmitz, L.