Consultez les articles du Bulletin Aves !
Aves, 10/3 | 1973 | 153-160
Joiris, C. & Martens, P.
A series of 16 unhatched eggs of birds of prey were collected in Belgium in 1971, and analysed in order to determine their level of contamination with organochlorine pesticides. All the samples contained pesticide residues, the results ranging from 0,02 to 7,4 ppm total residues. As a rule, DDT and its metabolites are the most abundant contaminants. Two exceptions are : Montagu's Harrier (dieldrin being the most abundant in one sample) and Kestel (BCH being the most abundant in the three eggs analysed). Utilizing the total DDT-content as a criterion, the most contaminated species are : Sparrowhawk, Long eared Owl and, partly, Tawny Owl (range : 2,2 to 6,9 ppm). The other eggs are much less contaminated (from 0,02 to 1,2 ppm total DDT) : Buzzard, Honey Buzzard, Montagu's Harrier, Kestrel and, partly, Tawny Owl. These differences in contamination levels are probalby to be explained by prey-specificity differences between raptor birds (either birds- or mammals easting raptors).