170 research outputs found
Strong population decline of Citril Finches Carduelis citrinella at postbreeding sites in the northern Black Forest
Ein Vergleich der Bestände von Zitronenzeisigen an traditionellen, nachbrutzeitlichen Sammelplätzen im Nordschwarzwald ergab signifikante Rückgänge in vier von fünf Gebieten. Bei anhaltendem Rückgang ist mit dem völligen Verschwinden der Art im Nordschwarzwald zu rechnen. Mögliche Ursachen bestehen in der Änderung der Landnutzung durch die Aufgabe der traditionellen Almwirtschaft und durch Wiederbewaldung der Hochlagen. Außerdem ist ein negativer Einfluss durch eine deutliche Klimaveränderung und damit verbundene Veränderung in der Schneeauflage, Vegetation und den Wachstumsperioden wahrscheinlich. Deutliche Populationsrückgänge in benachbarten Gebieten wie den Alpen (Rückgang der Dispersion) könnten ebenfalls ein wichtige Rolle für die Populationsentwicklung des Zitronenzeisiges an der Arealgrenze im Nordschwarzwald spielen.A comparison of Citril Finch populations at traditional postbreeding assembling sites in the northern Black Forest comfirmed a significant decline of the species. Possible reasons may be found in changes in land use due to the end of traditional pasturing and reforestation in the mountainous areas. Additionally a negative influence due to global warming and the linked change in vegetation composition and periods of growing is highly likely. Probable macroecological reasons such as the decline of populations in neighbouring areas (e.g . Alps) and the reduction of population exchange by dispersion may play an important role for the decline of Citril Finches at their northern areal boundaries as well
Successful broods of a hybrid between redstart Phoenicurus phoenicurus and black redstart Phoenicurus ochruros
Zwischen 2000 und 2002 wurde ein phänotypisch intermediärer Hybride aus Gartenrotschwanz Phoenicurus phoenicurus und Hausrotschwanz P. ochruros während der Brutzeit im Nordschwarzwald beobachtet (Ruhestein, 950 m NN; Kreis Freudenstadt; Baden-Württemberg). Solche Rotschwanz-Hybriden wurden schon mehrfach im Freiland nachgewiesen. Angaben zu Habitat, Bruterfolg, Nachwuchs und Fitness von Hybrid-Rotschwänzen im Freiland sind allerdings sehr selten. Es ist wahrscheinlich, dass die enge Nachbarschaft von Bruthabitaten beider Arten das Auftreten von Hybriden begünstigen. Der hier beschriebene Vogel brütete drei Jahre hintereinander erfolgreich mit einem Hausrotschwanz-Weibchen und zog mindestens zwei bis drei Jungvögel pro Brut groß.Between 2000 and 2002 a male phenotypical intermediate hybrid between redstart Phoenicurus phoenicurus and black redstart P. ochruros. was observed regularly during the breeding season in the Northern Black Forest (Ruhestein, 950 m NN; district Freudenstadt; Germany). Similar redstart hybrids have been documented several times. However, descriptions on habitat selection, breeding success, offspring and fitness of such hybrids in the field are very rare. It is highly likely that close neighbourhood of breeding habitats of the two redstart species is responsible for the occurence of mixed broods. The hybrid documented in this study was breeding successfully each year with a black redstart female and raised at least two to three fledglings per brood
Predation strategy of the Eurasian Jay (Garrulus glandarius) and antipredator response by the Citril Finch (Serinus citrinella)
És prou conegut que el gaig Ă©s un predador important de nius d'ocells. AquĂ es descriu la conducta de cerca d'un gaig el 7 de juny de 2002 a l'estaciĂł d'esquĂ de la Vansa, al Prepirineu catalĂ . Durant un perĂode de quatre minuts, l'ocell va inspeccionar quatre pins negres a la cerca de possibles nius d'altres ocells. El gaig va examinar les zones mĂ©s espesses de l'arbre, començant per les parts inferiors de les branques laterals i va acabar a la capçada. El comportament de la cerca va despertar el rebuig de mitja dotzena de llucaretes, probablement parelles que niaven als voltants, que seguien el gaig mentre es movia pels arbres, alhora que emetien crits antipredadors. La Vansa Ă©s una Ă rea amb una alta densitat reproductora de llucareta (12-15 parelles/10 ha), la qual cosa converteix els nius d'aquesta espècie probablement en un dels objectius preferits per a la depredaciĂł del gaig
Naturbeschreibung – Naturgeschichte [Tagung »Text – Kontext / Analyse – Interpretation: Methodische und methodologische Grundfragen der Geistes- und Kulturwissenschaften am Beispiel der Kant-Forster-Kontroverse«, 24.09.-26.09.2009, Halle.]
Fully Bayesian Inference for Structural MRI: Application to Segmentation and Statistical Analysis of T2-Hypointensities.
Aiming at iron-related T2-hypointensity, which is related to normal aging and neurodegenerative processes, we here present two practicable approaches, based on Bayesian inference, for preprocessing and statistical analysis of a complex set of structural MRI data. In particular, Markov Chain Monte Carlo methods were used to simulate posterior distributions. First, we rendered a segmentation algorithm that uses outlier detection based on model checking techniques within a Bayesian mixture model. Second, we rendered an analytical tool comprising a Bayesian regression model with smoothness priors (in the form of Gaussian Markov random fields) mitigating the necessity to smooth data prior to statistical analysis. For validation, we used simulated data and MRI data of 27 healthy controls (age: [Formula: see text]; range, [Formula: see text]). We first observed robust segmentation of both simulated T2-hypointensities and gray-matter regions known to be T2-hypointense. Second, simulated data and images of segmented T2-hypointensity were analyzed. We found not only robust identification of simulated effects but also a biologically plausible age-related increase of T2-hypointensity primarily within the dentate nucleus but also within the globus pallidus, substantia nigra, and red nucleus. Our results indicate that fully Bayesian inference can successfully be applied for preprocessing and statistical analysis of structural MRI data
Fully Bayesian Inference for Structural MRI: Application to Segmentation and Statistical Analysis of T2-Hypointensities.
Breeding ecology and nest site selection in allopatric mainland Citril Finches Carduelis [citrinella] citrinella and insular Corsican Finches Carduelis [citrinella] corsicanus
The outsider advantage: Interviewing planners and other elites in the Polish-German borderland
As conducting interviews with elites is increasingly common, an important debate has emerged around the researcher’s positionality as an insider/outsider also in a geographic sense. Three standpoints can be distinguished. Initially, some emphasised the advantages of the insider in eliciting interesting and sometimes even sensitive information from informants. More recently, several scholars suggested
that this position is never stable. Our experiences are however more in line with those who demonstrat
ed the advantages of being an outsider. Coming from outside the study area may be particularly helpful when interviewing elites on sensitive issues such as contacts in a borderland with a troubled history, like between Poland and Germany. Our 38 interviews reveal three patterns. First, blaming the
other side is not unusual on both sides of the border. Second, de-emphasising the importance of cooper
ation is more common on the Polish side, but also occurred on the German side. Finally, a discourse of re-establishing the historically coherent region is clearly present on the German side, but lacks almost entirely on the Polish side. It is doubtful whether we would have been able to elicit such attitudes from both studied groups had we belonged to either one of them
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