Displaying behaviour and mating system in the Siberian Spruce Grouse (Falcipennis falcipennis Hartlaub 1855)

Summary The Siberian Spruce Grouse (Falcipennis falcipennis) is a species endemic to far-eastern Russia and a close relative toF. canadensis andF. franklinii of North-America. Prior to this study, little was known about the display behaviour, social organisation and seasonal movements of this grouse. We investigated these topics in 1990–1997, in 2 areas, 100 km N and 200 km NW of Komsomolsk/Amur. We caught, measured and marked 80 individuals. We determined the age of cocks by the size of combs and the length of neck feathers. Spatial organisation of the local population was studied by equipping 60 birds with transmitters and following them all-year-round.During the reproductive period males and females were territorial. Winter flocks (2–6 birds) break up by late March or early April, and spring flocks break up 1 month later. Cocks were present at the display ground from April 1 to May 25. Females visited the display grounds from April 25 to May 10. Eggs were laid between May 7 and May 20. The main display performances of cocks (upright posture and tail flicks, walks with tail swish, flutter jumps, flutter flights, drumming flights), courtship and agonistic behaviour were analysed from photographs and video recordings. Three-year-old cocks carried out most of the copulations. During the high season of display, we recorded activity (morning and evening displays, moving versus roosting) during continuous observations and counted flutter jumps, flutter flights and drumming flights.Parts of the displays of the Siberian spruce grouse are more diversified than those of the North-American species. The communication system is perfectly adapted to the dense habitat of the mountain taiga. Different acoustic signals for communication at very short, medium and longer distances seem to have evolved under specific predation pressure. The territorial system is very flexible, ranging from individual display grounds to an arena-like structure. The mating system is polygyny.

---

Balzverhalten und Paarungssystem des Sichelhuhns (Falcipennis falcipennis Hartlaub 1855)

Zusammenfassung Das Sichelhuhn (Falcipennis falcipennis) als endemisches Raufußhuhn des Fernen Ostens Russlands ist eng verwandt mit den nordamerikanischen FichtenhühnernF. canadensis undF. franklinii. Von 1990–1997 wurden Ökologie und Verhalten dieser Art in zwei Gebieten (100 km N und 200 km NW von Komsomolsk am Amur) studiert. 80 Vögel wurden gefangen, vermessen und markiert. Zwei Maße (Größe der Überaugenwülste und Halsfederlänge) gestatten eine Altersbestimmung der Hähne. 60 besenderte Vögel lieferten rund um das Jahr Daten zu Raum- und Habitatnutzung, Reproduktion und Mortalität. Individuelle Markierung und Ortung zu beliebigen Zeiten erleichterten auch die Verhaltensstudien. In der Reproduktionsperiode besaßen sowohl Hähne als auch Hennen Reviere. Winterflüge aus 2–6 Vögeln lösten sich Ende März/Anfang April auf; die Frühjahresgruppen einen Monat später. Die Hähne waren im Mittel zwischen 1. April und 25. Mai an den Balzplätzen anzutreffen, die Hennen erschienen dort zwischen 25. April und 10. Mai. Zwischen 7. und 20. Mai erfolgte die Eiablage. Die wichtigsten Elemente des Territorialverhaltens (Aufrechthaltung mit Schwanzspreizen, Imponierläufe mit Schwanzfederzischen, Flattersprünge, Flatterflüge und Trommelflüge), Revierverteidigung und Werbung werden nach Foto- und Videoaufzeichnungen beschrieben. Dreijährige Hähne vollzogen die meisten Paarungen. Zwischen 1. und 9. Mai, wenn Werbe- und Paarungsverhalten kulminieren, wurden durch Ganztagsbeobachtungen Morgen- und Abendaktivität, Ortsveränderungen und Ruhephasen quantitativ erfasst, ebenso der tägliche Anteil von Flattersprüngen, Flatter-und Trommelflügen. Im Vergleich zu den nordamerikanischen Geschwisterarten sind Teile des Verhaltensrepertoires des Sichelhuhns zur Balzzeit stärker differenziert. Das Kommunikationssystem ist an dichte Habitate der borealen Bergtaiga angepasst: Verschiedene akustische Signale, die auf sehr kurze, mittlere and längere Distanzen wirken, sind offenbar in Anpassung an den spezifischen Feinddruck entstanden. Das Reviersystem erscheint flexibel: Die Spanne reicht von solitär agierenden Hähnen bis zu Arena — ähnlichen Balzplätzen. Das Paarungssystem ist Polygynie.

     

Actin pedestal formation by enteropathogenic Escherichia coli and intracellular motility of Shigella flexneri are abolished in N-WASP-defective cells

In mammalian cells, actin dynamics is tightly controlled through small GTPases of the Rho family, WASP/Scar proteins and the Arp2/3 complex. We employed Cre/loxP-mediated gene targeting to disrupt the ubiquitously expressed N-WASP in the mouse germline, which led to embryonic lethality. To elucidate the role of N-WASP at the cellular level, we immortalized embryonic fibroblasts and selected various N-WASP-defective cell lines. These fibroblasts showed no apparent morphological alterations and were highly responsive to the induction of filopodia, but failed to support the motility of Shigella flexneri. In addition, enteropathogenic Escherichia coli were incapable of inducing the formation of actin pedestals in N-WASP-defective cells. Our results prove the essential role of this protein for actin cytoskeletal changes induced by these bacterial pathogens in vivo and in addition show for the first time that N-WASP is dispensible for filopodia formation.     

Modified dispersal‐related traits in disjunct populations of bird‐dispersed Frangula alnus (Rhamnaceae): a result of its Quaternary distribution shifts?

Many European tree species survived Pleistocene glaciations in Mediterranean refugia and rapidly recolonized temperate Europe afterwards. Inter‐ and postglacial migration processes are assumed to have catalized evolutionary optimizations of dispersal‐related traits, but up to now empirical evidence is lacking in vertebrate‐dispersed plants. We investigated if south Iberian glacial relict and central European “colonizer” populations of the bird‐dispersed tree Frangula alnus have experienced differentiations of dispersal‐related traits which increase the mobility of northern populations. A comparison of lifetime reproductive strategy, disperser guilds, ripening phenology, and fruit design revealed considerable differences. Compared to south Iberian conspecifics, central European plants were considerably smaller and experienced a highly accelerated generation turnover. In south Iberian populations seed dispersal was carried out almost completely by resident birds which occurred in constant abundances throughout the ripening season. In contrast, central European seeds were dispersed by migrants whose abundances changed considerably during the ripening season. Several bird species were involved in both study areas but rendered different importance for seed dispersal. The fruit ripening pattern was highly asynchronous throughout the ripening season in south Iberia, while central European trees showed a complex ripening sequence which resulted in a significant correlation between fruit abundance and changing disperser availability. Central European fruits were smaller and showed a considerably smaller seed load than south Iberian fruits, thus presumably being more attractive for their small‐sized main dispersers (Sylvia warblers). Chemical analyses revealed significant differences in contents of water, glucose, fructose, proteins, ash. and phenolic compounds. The extensive differentiation of dispersal‐related traits in F. alnus suggests that even weak selective pressures by frugivores may induce evolutionary adjustments of dispersal traits over large time scales. We suggest that the differences we observe today evolved during the species' distribution shifts in the Quaternary.     

Host-Guest Chemistry and Chemical Sensors: FT-IR-Analysis and Spectra Simulation of CDCl<Subscript>3</Subscript> Inclusion

Host-guest principles are put into action advantageously by cyclodextrins that give remarkable sensor responses to halogenated hydrocarbons on mass-sensitive devices such as QMB (quartz micro balance) and SAW (surface acoustic wave) resonators. Modifications of the structure can tune the compound to different analytes and molecular modeling allows us to understand and predict specific host-guest interactions. The FT-IR analysis of CDCl₃, incorporated into a partially methylated cyclodextrine, yields an astonishingly strong band shift of about 50 cm^-1 to lower wave numbers, in contrast to the permethylated product that shows a displaced band of 10 cm^-1 for the C-D stretching vibration. The explanation can be given by semiempirical methods and force field calculations. Two CDCl₃ binding sites are revealed, one being a multicentered inclusion ([(n)\tilde] ~ 2195  cm^-1{\tilde\nu}\sim 2195\;cm^{-1} of CDCl₃ at the upper rim of the #-cyclodextrine cone, whereas the other is incorporated within the cavity ([(n)\tilde] ~ 2240  cm^-1{\tilde\nu}\sim 2240\;cm^{-1}.     

Das Pflanzenreich auf der Wiener Weltausstellung im Jahre 1873

Ohne Zusammenfassung     

Ein BastardPrimula auricula L. XP. Clusiana Tausch

Ohne Zusammenfassung     

Optical picosecond studies of bacteriorhodopsin containing a sterically fixed retinal

The photochemical behaviour of an analogous bacteriorhodopsin (9,12-Ph-BR) which contains the sterically fixed 9,12-phenylretinal has been investigated with picosecond spectroscopy. The following results have been obtained. No ground-state intermediate photoproduct is found in agreement with the previous observation that 9,12-Ph-BR does not exhibit proton pumping under illumination. The excited singlet state has a lifetime of τ_S = 10 ± 2 ps. This lifetime agrees favourably with the value calculated from the radiative lifetime τ_rad = 6.2 ns and the fluorescence quantum efficiency of 1.2·10⁻³. Excited-state absorption occurs which results in fluorescence in the ultraviolet region. These various observations differ drastically from the corresponding findings on bacteriorhodopsin. Most important for an understanding of the differences is the fact that 9,12-phenylretinal does not isomerize in the protein's binding site in contrast to retinal. Our data therefore suggest that the formation of the intermediate K observed in bacteriorhodopsin is accompanied by the all-trans to 13-cis isomerization.