Le Bulletin AVES Volume 36 - n° 4 - 1999 [Retour]

WEISERBS, A. & JACOB, J.-P. - Etude de la population de Perriche jeune-veuve (Myiopsitta monachus) à Bruxelles - pp. 207 - 223 Résumé : La Perriche jeune-veuve niche à Bruxelles depuis 1979. Au cours des années 1980, la progression s'est traduite par la formation de sept nids communautaires et la population atteignit 30-35 couples. Depuis lors, cette petite population a fluctué et une légère expansion a été constatée en 1999-2000. Cette population est la seule connue en Belgique et représente une des implantations les plus septentrionales de cette espèce originaire d'Amérique du Sud. Study of the population of Monk Parakeet (Myiopsitta monachus) in Brussels. Summary : Monk Parakeet have bred in Brussels since 1979. During the eighties, seven communal nests have been built and the population increased to 30-35 pairs. In 1999, this small population amounted to 50-60 individuals on three sites. Several new nests and sites have been irregularly occupied since. Six nests are located on artificial supports, two of them having been occupied for 10-20 years (see pictures); five other nests are located in trees (parks, tree rows) and are not continuously used. Most nests are close to each other (Fig. 1). On two occasions, Magpie nests seem to have played an attractive role (attempt at occupation and visual stimuli). Breeding of feral pigeons and possibly of Stock Doves has been observed in those nests. This population is the only one in Belgium and one of the most northerly implantation in Europe (Fig. 2). Adverse climatic conditions might constitute a limiting factor to its development, as the species is clearly dependent on artificial feeding in winter. A survey of neighbours indicates a positive perception of the species presence. JACOB, J.-P. - Evolution récente de la population nidificatrice du Grèbe huppé (Podiceps cristatus) en Wallonie et Bruxelles. - pp. 225 -244 Résumé : La population wallonne et bruxelloise du Grèbe huppé comptait 854 adultes à la mi-mai 1995 et 287 couples nicheurs au moins en 1995 . Le Grèbe huppé niche maintenant dans presque toutes les régions. L'augmentation récente est due surtout à la progression en Meuse et aux barrages de l'Eau d'Heure. Une fois colonisés, la plupart des sites sont occupés avec régularité. La population tend aussi à croître pendant assez longtemps sur de nombreux sites. Recent evolution of the breeding population of the Great Crested Grebe (Podiceps cristatus) in Wallonia and Brussels Summary : The Great Crested Grebe population in Wallonia and Brussels amounted to 854 adults in mid-may 1995 and at least 287 breeding pairs in 1995 (see Table 1). The Great Crested Grebe now breeds in most regions (Fig.1). The population increase (Table 2 and Fig. 2) results mostly from progresses in the Meuse river and Eau d'Heure lake. Once colonised, most sites remain regularly occupied. Populations also tend to increase for long periods on many sites. Great Crested Grebes occupy artificial ponds, industrial sites, rivers and less frequently dams (Table 6). This unprecedented high numbers can be explained by the availability of potential breeding sites, the abundance of fish and the protection given to the species. Furthermore, the repetition of mild winter may have improved winter survival, in particular of the less migrating populations. JACOB, J.-P., DE LIEDEKERKE, R., PAULUS, F., LOLY, P., PAQUET, J.-Y. & RABOSEE, D. - Chronique ornithologique : janvier-octobre 1995 - pp. 245 - 267