Norbert Kenntner

Eleven white-tailed sea eagles (WSEs) (Haliaeetus albicilla) collected in Finland between 1994 and 2001 were examined for their causes of death, including analyses of ubiquitous environmental contaminants and parasites. Four WSEs died due to electrocution. Two were lead poisoned and another had fragments of a lead bullet in its gizzard. An 11-year-old female drowned entangled in fishing gear, but also had mercury levels in its liver and kidneys known for detrimental physiological effects. One WSE was evidently killed by an intraspecific conflict, which was also assumed to be with another bird. The mortality factors of two WSEs could not be clarified, but one had a lead level of 4.604 μg g−1 in its liver, indicating high lead exposure at a clinically relevant concentration. All organ levels of chlorinated pesticides, polychlorinated biphenyls, and cadmium were moderate and not harmful for birds of prey. Seven helminth species, but no ectoparasites or coccidians, were found in 8 of 10 WSEs investig...

Concentrations of the organochlorine pesticides hexachlorobenzene (HCB), gamma-hexachlorocyclohexane (gamma-HCH), DDT and its metabolite p,p'-dichlorodiphenyldichloroethylene (DDE), and seven polychlorinated biphenyl (PCB) congeners were analyzed in livers and adipose tissue samples of 145 white-tailed eagles found dead or moribund in Germany from 1979 to 2001. Most birds were found in the region of the former German Democratic Republic where the insecticide DDT was used until 1988. Therefore, our samples represent mainly residue data of specimens following the ban of DDT in these regions. Contaminant levels of 127 immature and adult birds found between the years 1990 and 2001 were in general below threshold levels known for detrimental effects. The highest level of sigmaDDT was detected in an adult bird found dead in 1979. Residues of most organochlorines were highly significantly correlated between hepatic and adipose tissue. Concentrations of sigmaDDT increase during aging, whereas only the levels of the higher-chlorinated PCBs were higher in tissues of adult birds compared with the younger age classes. Hepatic residues of sigmaDDT and HCB and the ratio of sigmaDDT to sigmaPCB, respectively, were significantly declining from 1990 to 2001. The indices given for body condition of specimen were significantly correlated with liver concentrations, indicating higher residues in more emaciated birds.

The northern goshawk (Accipiter gentilis) is a top predator in the terrestrial food web of large parts of the Holarctic. Due to its sedentary nature and well-investigated feeding ecology, it represents the most suitable bird of prey species in continental Europe for monitoring environmental pollutants. We analyzed the levels of organochlorine pesticides, polychlorinated biphenyls (PCB), and nonessential heavy metals in organ samples of 62 free-ranging northern goshawks found dead or injured in Germany from 1995 to 2001. Our results indicate significant differences in the contaminant burden of northern goshawks between three regions in Germany. Presumably, these differences were caused by different application periods and legislative restrictions before the German reunion, especially for the use of DDT in agriculture and forestry. Extraordinarily high residues of PCBs and DDE, the main metabolite of DDT, were found mainly in livers of northern goshawks inhabiting Berlin. Body condition is highly negatively correlated with the contamination level of the individual, especially for the persistent and lipophilic organochlorines and for mercury. PCB concentrations in hepatic tissue increase rapidly with age, and birds in their first summer had significantly lower levels than birds in their first winter or older. Adult female northern goshawks from Berlin had significantly higher hepatic concentrations of most of the higher-chlorinated PCBs and of cadmium than males from the same region. Cadmium residues were in general higher in renal tissue than in hepatic tissue, and cadmium levels in kidneys increased with age. Lead concentrations indicative of acute lead poisoning were detected in one bird and suggested in two others. All other heavy metal concentrations were low and represent background levels for birds of prey in Germany.

Residues of the potentially toxic metals lead, mercury, and cadmium were analyzed in liver and kidney tissue of 61 free‐ranging white‐tailed eagles (Haliaeetus albicilla) found dead or moribund in Germany and Austria between 1993 and 2000. Highest values and the widest range were detected for lead in liver and for mercury in kidney tissue. Lead concentrations considered to induce lethal lead poisoning (>5 ppm wet wt) were determined in 28% of liver samples. Lead fragments were detected in the gizzards of two specimens, presumably having died from lead intoxication. Histopathological findings in a recently dead white‐tailed eagle indicating acute lead exposure comprise degenerative Purkinje cells in the cerebrellum and inclusion bodies in renal tubular cells. Mercury residues in organs are decreasing compared to former studies in periods when organomercury compounds were used as seed dressing. All cadmium values were low or are at background levels in white‐tailed eagles. The present study clearly identifies lead as a toxic metal poison in white‐tailed eagles in Germany and Austria.