Zeitaufwand für das Ernten und Verstecken von Kiefernsamen bei Dünnschn?bligen Tannenh?hern (Nucifraga caryocatactes macrorhynchos) im Fernen Osten Russlands

Zusammenfassung In einem Vorkommen des Dünnschnäbligen Tannenhähers an der Küste des Ochotskischen Meeres im Fernen Osten Sibiriens wurde das Ernten und Verstecken von Samen aus den Zapfen der Zwergzirbelkiefer (Pinus pumila) untersucht. Der Inhalt von durchschnittlich 2,8 Zapfen, das sind etwa 80 Samen, wurde in der gefüllten Kehltasche transportiert und auf eine Anzahl unter niedriger Zwergstrauchvegetation gelegener Bodenverstecke verteilt. Die Verstecke wurden in annähernd linearer Anordnung ohne Bevorzugung einer bestimmten Himmelsrichtung angelegt. Die Versteckserien enthielten im Median 79, maximal mehr als 120 Samen, das Einzelversteck durchschnittlich 19,6 Samen. Das Ernten und Leeren eines Zapfens geschah im Schnitt innerhalb von 47 s. Für das Verstecken einer Füllung des Kehlsacks benötigten die Vögel ca. 170 s. Für das gesamte Beschaffen und Verstecken eines einzelnen Kiefernsamens errechnet sich ein durchschnittlicher Zeitbedarf von 3,26 s. Nach 20 Tagen war der Zapfenvorrat in der lokalen Kiefernpopulation erschöpft. Jeder Häher hat nach den Hochrechnungen bis zu 100.000 Samen vergraben.

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Harvesting and caching capacities of Thin-billed Nutcrackers in the Russian Far East

Summary At the Ochotskian sea coast Thin-billed Eurasian Nutcrackers (Nucifraga caryocatactes macrorhynchos) harvested seeds of ripe cones of the brush pinePinus pumila in late summer. The mean number of seeds carried in their sublingual pouch was 80, which respresents the harvestable contents of 2.8 cones. These were distributed in an average of 5 caches, exclusively in the soil under low tundra vegetation. Caches were organized in nearly straight lines. Series contained a mean of 82.7 seeds, single caches a mean of 19.6 seeds. Plucking one cone and harvesting its seeds took 47 seconds on average. The caching of a complete pouchful took on average 123.4 seconds. The time invested for harvesting and caching one single seed was calculated at 3.26 seconds. Within three weeks in July, an average individual bird was calculated to have cached a total of up to 100,000 seeds.

     

Inhibition of growth of Leishmania mexicana mexicana by Leishmania mexicana amazonensis during "in vitro" co-cultivation

Inhibition of one Leishmania subspecies by exometabolites of another subspecies, a phenomenon not previously reported, is suggested by our recent observations in cell cloning experiments with Leishmania mexicana mexicana and Leishmania mexicana amazonensis. Clones were identified using the technique of schizodeme analysis. The phenomenon observed is clearly relevant to studies of parasite isolation, leishmanial metabolism, cross-immunity and chemotherapy.     

Tn10 mutagenesis in Azotobacter vinelandii

Summary The tetracycline-resistant transposon Tn10 and its high-hopper derivative Tn10HH104 were introduced into the Azotobacter vinelandii genome using suicide conjugative plasmids derived from pRK2013. Several types of mutants induced by either of these elements are described. Nif^- mutants (deficient in nitrogen fixation) were easily isolated, whereas the isolation of other mutant types (auxotrophs, sugar non-users) required special selection conditions. The characterization of the mutations as transposon insertions was often complicated and sometimes required a combination of genetic and physical tests. A common source of complication, the existence of double inserts, was found among the mutants induced by Tn10HH104 but not among those induced by Tn10. Both the high-hopper and the wild-type element proved to undergo secondary transpositions, albeit at different frequencies. Another type of complication, the existence of heterozygotes, occurred because of the high level of redundancy of the A. vinelandii genome.     

Die Entwicklung der Laut?u?erungen bei der Graugans (Anser anser)

Zusammenfassung Das Lautrepertoire von sechs handaufgezogenen Graugänsen wurde in individuellen Längsschnitten vom Schlüpfen bis zum Alter von 100 Tagen mit sonagraphischer Methode analysiert. Die Einteilung des Repertoires erfolgte nach drei verschiedenen Kriterien: Klang, Sonagramm und Kontext. Im jugendlichen Repertoire ließen sich 4 Rufklassen voneinander trennen. Im Laufe der Jugendentwicklung veränderten sich vor allem die phonetischen Parameter der Rufe, während die syntaktischen weitgehend konstant blieben. Nach einem Anstieg in der ersten Woche fiel die Tonhöhe der Rufe bei allen untersuchten Individuen und Rufklassen gleichmäßig ab. Der Stimmbruch, meßbar an der Zunahme geräuschhafter Komponenten, war ein kontinuierlicher, langfristiger Prozeß. Die Individualität war nicht in einem einzelnen, wohl aber in der Kombination mehrerer Merkmale faßbar. Die Geschlechter waren schon früh an Unterschieden in der Tonhöhe erkennbar. An sonstigen ontogenetischen Veränderungen innerhalb des Untersuchungszeitraumes konnten die Erweiterung des Repertories durch Aufspaltung und Reifung sowie ein möglicher Verlust von Rufklassen beobachtet werden.

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Juvenile development of vocalizations in Greylag Geese (Anser anser)

Summary The juvenile vocal development of six Greylag Geese from hatching up to the age of 100 days was analysed by using sonagraphic methods. The calls were classified by means of the acoustic phenomenon, sonagrams, and context criteria. The juvenile repertoire included four main call types. During ontogeny, changes of call parameters mainly referred to phonetic characteristics, whereas syntactic parameters remained more or less constant. The frequency pitch of calls changed to higher levels during the first week of development while in older goslings this parameter decreased constantly. This held true for each individual and call type. Breaking of the voice, defined as an increment of noisy parts in the vocalizations, is described as a continuous long term process. Structural individuality of calls apparently was not based on one single parameter, but on the combination of several ones. Sex differences were found in the pitch of vocalizations, correlating with different body weights of male and female geese. Additional developmental processes of the vocal repertoire included differentiation, maturation of new call types, and apparent suppression of juvenile ones. The functional organization of the juvenile call system in Greylags is discussed.

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Herrn Dr. Hans Löhrl zum 75. Geburtstag gewidmet     

Inositol trisphosphate and calcium mobilisation in permeabilised enterocytes

Saponin-permeabilised epithelial cells isolated by hyalurodinase incubation from chicken small intestine were used to study 45Ca uptake into intracellular stores. At low (6.7 X 10(-7) M) free Ca2+ concentration most of the Ca2+ appears to be taken up into non-mitochondrial stores, whilst the mitochondria seem to play a major role at high (2 X 10(-5) M) Ca2+ concentration. Addition of inositol trisphosphate (IP3) causes a rapid and reversible release of 45Ca from non-mitochondrial stores, with a half-maximal effect of approximately 1 microM.     

Aging and cerebral aminopeptidase activity

A comparative study of brain aminopeptidase activity between 18 month old male rats and young adults of 3 months has been carried out utilizing the arylamides Leu-, Arg-, Lys-, Tyr- and Asp-beta-naphthylamide as substrates. Statistical analysis of results showed no significant differences either in areas studied or for enzymatic activities detected when both ages were compared. Two different patterns of regional distribution of enzymatic activity were observed: One came to be as a result of the use of Lys-, Arg-, Leu- or Tyr-beta-naphthylamide and the other as a result of the use of Asp-beta-naphthylamide.     

Cloning and expression of human salivary-gland kallikrein in Escherichia coli.

CDNA clones for human kallikrein have been identified in a cDNA library constructed from mRNA of human salivary gland. The entire coding sequence for preprokallikrein and for the 5'- and 3'-untranslated regions were isolated by using a mixture of oligonucleotides corresponding to amino acids 51-56 of human urinary kallikrein and one oligonucleotide corresponding to amino acids 233-238 of human pancreatic kallikrein. The DNA sequence proved that, with the exception of two amino acid exchanges, kallikrein of the human salivary gland is identical with pancreatic kallikrein. Salivary gland and renal kallikrein was expressed in Escherichia coli from plasmid pKK223-3 under the control of the tac promoter. The protein was identified by Western-blot analysis and by demonstration of its specific proteolytic activity.     

Thiolutin inhibits utilization of glucose and other carbon sources in cells of Escherichia coli

Thiolutin was found to inhibit the utilization of glucose and other growth substrates in Escherichia coli. The inhibition was detected by a sharp drop of the respiration rate after addition of the antibiotic. The actual function affected was allocated to the cytoplasmic membrane of the bacterial cells by the following evidence: