Frequency analysis of the songs of 90 European passerine species shown a correlation with body weight. In a number of species a dependence on habitat was found.Various physiological parameters of homeothermic vertebrates such as heart beat, respiratory and metabolic rates exhibit a strong dependence on body weight z. A similar relation was suggested for the vocalization of birds by Schwartzkopff z. This problem area was examined in a comprehensive study of the song frequencies of European passerine birds. Material and methods. The songs of 90 passerine speciesrecorded in the open field on UHER and NAGRA tape recorders were analyzed using a 1/3-octave filter (TOA 111) thus yielding species-specific vocalization spectra. At least 3 song sequences of each individual and of 3 individuals of each species were analyzed. Species-specific centre frequencies were found by calculating the geometric mean of each spectrum. These frequencies were compared with the body weights of the species. Mean body weights were taken from larger samples in the literature 3. Results.The figure 1 illustrates the relation found between song centre frequency and average body weight of the species studied. Frequencies range from 1.25 kHz (Corvus 212 o~ ta_ ~, .. fc=7204 W -0"24 ...: " 9 r=-O.77(p < 0.001) ~1' oe I~ 9 9 I I I i s I' O 2'o s'o soo 1ooog Body weight Relation between song centre frequency and average body weight of 90 European passerine species: The relation may be expressed by a regression function with high significantly correlation.corax) to 6.13 kHz (R. regulus), b.wt from 5.3 g (Regulus ignicapillus) to 1400 g (Corvus corax). The relation between centre frequency and body weight may be expressed by the regression function fr = 7.204 W -~ (fc in kHz and W in g). The correlation coefficient r has the value 0.77. This value is significant with p < 0.001. A closer analysis shows certain marked disparities for which ecological factors appear to be responsible. Thus species living in open habitats (field and meadow) exhibit higher frequencies than expected whereas the converse true for species occupying homogeneous habitats (rush) 4.Discussion. The relation found between mean song frequency and body weight shows that bird vocalization is highly dependent on constitution. As vocalization depends to a high degree on anatomical factors (length of trachea, resonance capacity etc.) as well as physiological factors (respiratory ratel) such a correlation is to be expected. It is interesting to note in this context that the value found for the exponent of the regression function (-0.24) corresponds closely to values for the regression functions for heart beat rate (-0.21 to -0.251,5,6) and respiratory rate (-0.26 ~) over body weight in homeothermic animals; it would appear that a general relation exists. Birds also have the capacity to adapt their vocalization to ecological factors. Studies reported previously, however, express one-sided points of view: body weight is either totally 7 or partly s ignored thus giving ecological factors pri...

Wild birds are considered a potential reservoir or a carrier of viral diseases and may therefore play a role in the epidemiology of economically important or zoonotic diseases. In 2001 and 2002, a survey with special emphasis on virus isolation in migrating waders and some other birds were conducted. In one of the most important inland resting sites for migratory waterfowl, tracheal and cloacal swabs were collected from 465 waders representing 19 different species, and 165 other birds that were not captured on purpose. A total of 42 avian viruses were isolated, 34 of these were identified as paramyxoviruses (PMVs). The majority of isolates came from waders and wild ducks, and were characterized as PMV-1. In contrast, PMV-4 was found in wild ducks only, PMV-6 was mainly detected in wader species. Four avian influenza viruses (AIVs), belonging to H4 and H3 haemagglutinin subtype, were isolated from wild duck species. Furthermore, four reo-like viruses were isolated from one particular wader species for the first time. The majority of virus positive birds were <1 year old and did not show any clinical symptoms. There was no evidence for the presence of West Nile virus in these birds. These results confirm that the restricted resting sites in Western Europe must be considered as important locations for the intra- and interspecies transmission of avian viruses.

Question: Can wild ungulates efficiently maintain and restore open habitats? Location: Brandenburg, NE Germany. Methods: The effect of wild ungulate grazing and browsing was studied in three successional stages: (1) Corynephorus canescens‐dominated grassland; (2) ruderal tall forb vegetation dominated by Tanacetum vulgare; and (3) Pinus sylvestris‐pioneer forest. The study was conducted over 3 yr. In each successional stage, six paired 4 m2‐monitoring plots of permanently grazed versus ungrazed plots were arranged in three random blocks. Removal of grazing was introduced de novo for the study. In each plot, percentage cover of each plant and lichen species and total cover of woody plants was recorded. Results: Wild ungulates considerably affected successional pathways and species composition in open habitats but this influence became evident in alteration of abundances of only a few species. Grazing effects differed considerably between successional stages: species richness was higher in grazed versus ungrazed ruderal and pioneer forest plots, but not in the Corynephorus sites. Herbivory affected woody plant cover only in the Pioneer forest sites. Although the study period was too short to observe drastic changes in species richness and woody plant cover, notable changes in species composition were still detected in all successional stages. Conclusion: Wild ungulate browsing is a useful tool to inhibit encroachment of woody vegetation and to conserve a species‐rich, open landscape.

The yellowhammer Emberiza citrinella is a common European bird that sings in dialects that for decades have been distinguished by the existence of one single element (called a ''specific''). In this study we looked into other possibilities for dialect discrimination, measuring 24 different variables. For the first time, multivariate statistics were used to discriminate dialect in yellowhammer song. Two similar dialects (XlB and XsB) that are not clearly defined in the literature were studied. Statistics incorporated (1) all variables, (2) no variables of ''specific'' elements, and (3) no variables under the influence of these ''specific'' variables. Multivariate statistics support dialect discrimination by ear and confirmed that only one element in yellowhammer song characterises dialect. In addition, we looked for local differences within two dialects and found that one local observation area showed a higher separation than the other sites (Meck1). However, as yet there is insufficient evidence for the existence of a new subdialect.

Following a steep decline, White Stork Ciconia ciconia populations in Germany are currently increasing, allowing us to examine potential density‐dependent effects on breeding dispersal. Our data suggest that the proportion of breeding dispersers has increased over time, indicating a density‐dependent component in nest‐site fidelity that may be linked to increased competition.