Table of Contents
ISRN Zoology
Volume 2011, Article ID 510202, 6 pages
Research Article

Dead Embryos despite Low Contaminant Loads in Eggs of Eleonora's Falcon

1Institute of Experimental Ecology, Ulm University, 89069 Ulm, Germany
2Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
3State Institute for Chemical and Veterinary Analysis of Food, 79114 Freiburg, Germany
4Smithsonian Tropical Research Institute, Balboa, Ancón 03092, Panama

Received 17 January 2011; Accepted 7 March 2011

Academic Editors: J. Joachim and I. Krams

Copyright © 2011 Marion Gschweng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


As a long-distance migrant which crosses more than 20 African countries, Eleonora's Falcons might have experienced a substantial accumulation of contaminants when returning to their breeding grounds. In 2004 and 2005, we collected 21 failed eggs from two colonies on Sardinia, Italy. We found a high percentage of dead embryos and suspected this was due to a high contaminant load. Despite this, the overall values for the contaminants analysed were rather low and lay within the range found in other raptor species. We analysed the eggs for residues of DDT (p,p′-dichlorodiphenyltrichloroethane), PCB (polychlorinated biphenyl), and heavy metals. Although infertile eggs seem to be correlated with the highest values of D D T , we did not find substantial values of any of the contaminants investigated. Because of the low world population of the species and varying reproduction rates in the colonies ranging from Cyprus to the Canaries, we highly recommend further censuses of the reproductive success of Eleonora's Falcon, including the examination of failed eggs.