Dortoirs urbains et dispersion des étourneaux Sturnus vulgaris au pays de Liège en 1978-79

During the last decade, sta rlings have built up considerable urban pop ulations in the ci ty of Liege, causing much trou ble t o inhabitants in the vicinity of roosting sites. This success might be attributed to the sheltered situation of the city in a deep valley, abunda nce of large trees in green spaces along banks of the river Meuse and in public parks, good situation amid pastures in the countryside, and on important migration routes. Before any attempt to redu ce this undesirable population, the city's authoriti es have promoted a research on the localisation, evaluation, evolution of roosting groups, as well as on pre - roosting routes and diurna l di spersion. It is clear that fluctuations in the attendance atone peculiar roosting site is understan dab le onl y in beeing replaced in the context of breeding cyc le, migration influx, weather cond i tions, food disponibilities, and man-made disturbance. Understanding starlings'population success and evolution needs long-term and large-scale coordinated researches at regional and continental level.