Inventarisatie in Nederland van de Huiszwaluw Delichon urbica in 1994

In 1994 at least 1250 quarters of 5 km grids were investigated on the presence of nests of the House Martin Delichon urbica) A minimum of 112.000 nests has been calculated. The decrease is 11% when compared with the results of the census of 1993 and in comparison with the index year 1990 a decrease of 17% has been calculated. The offer of artificial fabricated nests seemed to have the best results in the environment of present breeding places. Placing of young which were fallen out of their nests in temporary nests near the former nest were successful.