In recent years, the northern goshawk (Accipiter gentilis) has colonized suburban and urban areas in Berlin, Germany, and elsewhere in Europe. Because of the high proportion of feral pigeons (Columba livia f. domestica) in their diet, urban goshawks are suspected to have a high infection rate with Trichomonas gallinae. Therefore, from 1998 to 2001, we examined 269 nestlings from 90 nests for infection with T. gallinae by culture of swabs taken from the oropharynx and checked their oropharynx for the presence of caseous lesions indicative of trichomonosis. In 80% of the nest sites (nϭ90), at least one nestling was infected. The nestling infection rate with T. gallinae was 69.7% (nϭ33) in 1998, 73.0% (nϭ89) in 1999, 55.8% (nϭ77) in 2000, and 62.9% (nϭ70) in 2001. In total, 65.1% of the northern goshawk nestlings were culture positive for T. gallinae. Prevalence increased with the age of nestlings ( 2 ϭ12.4, nϭ269, dfϭ5, Pϭ0.03) and tended to increase with brood size ( 2 ϭ9.345, nϭ269, dfϭ4, Pϭ0.053). Caseous lesions were present in 12 nestlings (4.5%), but only 10 of these were culture positive for T. gallinae. Two nestlings (0.7%) had large caseous lesions (diameterϾ1 cm) characteristic of late-stage trichomonosis and died shortly after examination. It is suggested that the combination of a high prevalence of T. gallinae with a low rate of pathologicic changes is the result of an evolutionaryadapted parasite-host relationship.

Most temperate zone passerines defend territories during the breeding season. Commonly the size of these territories is estimated by plotting the singing locations of the males. However, an individual's activities need not be restricted to the area used for singing. So far, only little quantitative information has been available to determine how the singing territory relates to the activity range of male songbirds. Here, we present a study in which we used radio-tracking techniques to collect quantitative data on the spatial behaviour of 11 male territorial Nightingales (Luscinia megarhynchos). The results show that the singing territories made up only about 50 % of the activity ranges. Nevertheless, males spent over 90 % of the time within the singing territory. Singing territories almost never overlapped but activity ranges overlapped in all cases with the activity range of at least one neighbour. Males intruded into neighbouring territories throughout the season but the longest excursions were made before and during the female fertile period. The time spent for forays correlated significantly with song rate and territories of males with higher song rates in turn were less frequently the object of forays by other males. Song rate can be indicative of male quality, so that our findings strongly suggest that foray behaviour is related to male quality in nightingales.

Between September 1998 and December 2006, 87 injured or sick free-ranging white-tailed sea eagles (Haliaeetus albicilla) from Germany were admitted to the Small Animal Clinic, Free University of Berlin. Most birds were adults (43%) followed by nestlings/fledglings (26%), immature birds (18%), and juveniles (13%). In all age groups more females than males were presented. Birds with trauma-associated injuries were most often admitted, followed by lead toxicosis and feather anomalies in fledglings. Collision with anthropogenic structures was the most common cause of injuries in all age classes. Lesions caused by intraspecific aggressions were mainly found in adults, whereas a generalized feather abnormality (pinching off syndrome) was diagnosed only in fledglings. Of all birds, 25% were released back to the wild, 21% died, and 54% were not releasable or were euthanatized.

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.

Summary Most temperate zone passerines defend territories during the breeding season. Commonly the size of these territories is estimated by plotting the singing locations of the males. However, an individual’s activities need not be restricted to the area used for singing. So far, only little quantitative information has been available to determine how the singing territory relates to the activity range of male songbirds. Here, we present a study in which we used radio‐tracking techniques to collect quantitative data on the spatial behaviour of 11 male territorial Nightingales (Luscinia megarhynchos). The results show that the singing territories made up only about 50 % of the activity ranges. Nevertheless, males spent over 90 % of the time within the singing territory. Singing territories almost never overlapped but activity ranges overlapped in all cases with the activity range of at least one neighbour. Males intruded into neighbouring territories throughout the season but the longest excursions were made before and during the female fertile period. The time spent for forays correlated significantly with song rate and territories of males with higher song rates in turn were less frequently the object of forays by other males. Song rate can be indicative of male quality, so that our findings strongly suggest that foray behaviour is related to male quality in nightingales.