Evolution de la population d'Hirondelles de fenetre (Delichon urbicum) a BruxellesEvolution of the population of de House Martin (Delichon urbicum) in Brussels.

摘要

The House Martin was previously a common! species in the Brussels region. The first indication of a local decline dates back to the years 1978-1980. A drastic decrease of the breeding population during the eighties and early nineties lead the remaining population to a figure of about 50 to 60 breeding pairs since 1996 (the follow up of the species was a part of the program for environmental state survey in Brussels, effective since 1992). In the same way, the number of colonies was also going down : in 2003-2004 only four colonies were;, left in the whole Brussels territory (162 km(2)). A campaign conducted in 1995 for the placing of nest-boxes had some success in-a context of reduced mud availability for nest building. The follow-up of a colony through ringing suggests: that the return rate for young birds is almost zero, implying an important immigration rate. By contrast adults show some fidelity to the colony. The observed breeding success seems normal. However the remaining population is, extremely vulnerable and survival of the species in Brussels region is uncertain.