BackgroundUrbanization leads to substantial changes in natural habitats with profound effects on wildlife. Understanding behavioural responses to such environmental change is essential for identifying which organisms may adapt, as behaviour is often the first response to altered conditions. Individuals in more urbanized habitats may be expected to be more exploratory and bolder than their conspecifics in less urbanized habitats as they may be better able to cope with novel challenges.MethodsIn a two-year field study we tested ground beetles from differently urbanized forests for their exploratory behaviour (in a novel environment) and their risk-taking (death-feigning). In total, we tested ca. 3,000 individuals of four forest-dwelling ground beetle species from eight within-city forest patches. In the second year, we also transferred ca. 800 tested individuals of two species to the laboratory to test for consistent behavioural differences (i.e. personality differences) under standardised conditions.ResultsIndividuals were generally more exploratory in more urbanized than in less urbanized areas but only in one year of the study. Exploratory behaviour was not predicted by population density but increased with temperature or showed a temperature optimum. Exploration was consistent over time and individuals that were more exploratory also took higher risks.DiscussionWe demonstrated that species which are generally less directly exposed to human activities (e.g., most invertebrates) show behavioural responses to urbanization. Effects of urbanization were year-dependent, suggesting that other environmental conditions interacted with effects of urbanization on beetle behaviour. Furthermore, our results indicate that different personality compositions might cause behavioural differences among populations living in differently urbanized habitats.

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Fur das friiher angenommene Gleichgewicht zwischen den beiden valenztautomeren Formen A und B von (2-Hydroxypheny1imino)phosphoranen in Losung werden durch quantitative Untersuchung der temperaturabhangigen 'H-und 3'P-NMR-Spektren von 1 -10 die Gleichgewichtskonstanten und die thermodynamischen Parameter AH, AG und AS bestimmt. Die Lage des Gleichgewichts kann sowohl durch Substituenten als auch durch Variation des Losungsmittels stark beeinfluDt werden. Somit konnen gezielt Iminophosphorane oder Benzoxazaphospholine dargestellt werden. Iminophosphorane-Bxazaphospholine Valence TautomerismThe equilibrium constants and the thermodynamic parameters AH, AG, and AS for the earlier supposed equilibrium in solution of the two valence tautomeric forms A and B of (Zhydroxypheny1imino)phosphorane.s 1 -10 are obtained by quantitative NMR measurements. The position of the equilibrium depends strongly on the substituents as well as on the solvents used. Therefore it is possible to prepare either iminophosphoranes or benzoxazaphospholines. EinfuhrungBei der Reaktion von o-Aminophenolen bzw. o-Aminophenoxylen mit Dibromphosphoranen bzw. tert. Phosphinen entstehen in guten Ausbeuten (2-Hydroxypheny1imino)-phosphorane ' ). Wie wir bereits berichtet haben 3), Sind die 'H-NMR-und die 31P-NMR-Spektren temperatur-und losungsmittelabhangig, so da0 wir zur Interpretation dieser Befunde ein Gleichgewicht zwischen den valenztautomeren Formen (2-Hydroxypheny1imino)phosphoran (A) und 1,3,2-Benzoxazaphospholin (B) *) vorgeschlagen haben.Um diese Auffassung zu iiberpriifen, haben wir nun quantitative Kernresonanzuntersuchungen an den Iminophosphoranen 1 -10 durchgefuhrt. Damit ist es moglich, die das Gleichgewicht bestimmenden thermodynamischen Groljen zu ermitteln. Die Verbindungen 1, 2 und 7 sind bereits beschrieben l s 2 ) , wahrend 3-6 und 8-10 neu synthetisiert wurden.

ESR-spectra of iminophosphorane radicals exhibit a strong temperature dependent coupling constant of the phosphorus nucleus. This splitting is described by a superposition of π-σ- and hyperconjugative interactions with the free electron. Because of hindered internal rotation of the iminophosphorane group the hyperconjugation term becomes temperature dependent. Differences in the phosphorus data of ortho- and para-iminophosphorane radicals respectively may be explained by a change of the potential barriers hindering the internal rotation

P/ante Med. 59. Supplement Issue 1993 figurations at the axes. The only example for atropisomeric pairs in this plants is the fully dehydrogenated alkaloid dioncophyllacine A, which occurs as a mixture of its atropoenantiomers 4 and ent-4 (8).The first occurrence of atropo-diastereomeric representatives, though only in minor amounts, is also of pharmacological interest, since it now allows us to investigate the influence of the configuration at the axis on the biological activity. AcknowledgementsThis work was supported by the Deutsche Forschungsgemeinschaft (Graduiertenkolleg 'Magnetische Kernresonanz in vivo und ifl Vitro für die biologische und medizinische Grundlagenforschung") and the Fonds der Chemischen Industrie.