Testosteronkonzentrationen und Fortpflanzungsverhalten beim Japanischen M?vchen (Lonchura striata var.domestica, Estrildidae)

Summary No relation of singing, courtship and copulation activity with testosterone titers were found. Song activity was high with individual titers below 1200 pg/ml. Even copulations occurred during stages of the reproductive cycle with basal testosterone levels.     

Sex differences in the telencephalic song control circuitry in Bengalese finches (Lonchura striata var. domestica)

Bengalese finches, Lonchura striata, are extremely sexually dimorphic in their singing behavior; males sing complex songs, whereas females do not sing at all. This study describes the developmental differentiation of the brain song system in Bengalese finches. Nissl staining was used to measure the volumes of four telencephalic song nuclei: Area X, HVC, the robust nucleus of the arcopallium (RA), and the lateral portion of the magnocellular nucleus of the anterior nidopallium (LMAN). In juveniles (circa 35 days old), Area X and the HVC were well developed in males, while they were absent or not discernable in females. The RA was much larger in males but barely discernable in females. In males, the volumes of Area X and the RA increased further into adulthood, but that of the HVC remained unchanged. The LMAN volume was greater in juveniles than in adults, and there was no difference in the LMAN volume between the sexes. The overall tendency was similar to that described in zebra finches, except for the volume of the RA, where the degree of sexual dimorphism is larger and the timing of differentiation occurs earlier in Bengalese finches. Motor learning of the song continues until day 90 in zebra finches, but up to day 120 in Bengalese finches. Earlier neural differentiation and a longer learning period in Bengalese finches compared with zebra finches may be related to the more elaborate song structures of Bengalese finches.     

Characterization of eight polymorphic microsatellite loci from the Bengalese finch (Lonchura striata var. domestica)

Eight polymorphic microsatellite loci were isolated and characterized from the Bengalese finch (Lonchura striata var. domestica). In analyses of 25 individuals, the number of alleles ranged from two to four, and observed heterozygosity ranged between 0.05 and 0.73. At four loci, the observed heterozygosity of the Bengalese finches was significantly different from the expected heterozygosity. Primer sets were also tested in Javan munia (Lonchura leucogastroides), and the same eight loci were successfully amplified. In analyses of 20 unrelated individuals, the number of alleles ranged from one to seven, and the observed heterozygosity ranged from 0 to 0.56. In Javan munia, the observed heterozygosity differed significantly from the expected heterozygosity in only one locus.     

Statistical and Prosodic Cues for Song Segmentation Learning by Bengalese Finches (Lonchura striata var. domestica)

Juvenile songbirds learn their songs from adults. Birds do not simply learn songs verbatim but they sometimes learn parts of songs from multiple tutors and recombine these into one song sequence. How they segment a particular part and select that as a chunk and how these chunks are recombined are interesting questions to ask, because such segmentation and chunking is also considered to be a basic mechanism in human language acquisition. The song of the Bengalese finch has a complex syntax with variable note‐to‐note transition probabilities and could thus be suitable for the study of segmentation and chunking in birdsong. Thirty‐two male Bengalese finch chicks were reared in a large aviary where 11 adult tutors and 10 adult females were breeding freely. In this environment most male chicks learned songs from several tutors. The song note‐chunks that juveniles copied had higher transition probabilities and shorter silent intervals than did the boundaries of the chunks, suggesting that Bengalese finches segment songs using both statistical and prosodic cues. Thus, the Bengalese finch could prove to be an excellent model in which to study neural and behavioral mechanism for sound segmentation.     

Adult bengalese finches (Lonchura striata var. domestica) require real-time auditory feedback to produce normal song syntax

Songbirds develop their songs by imitating songs of adults. For song learning to proceed normally, the bird's hearing must remain intact throughout the song development process. In many species, song learning takes place during one period early in life, and no more new song elements are learned thereafter. In these so-called close-ended learners, it has long been assumed that once song development is complete, audition is no longer necessary to maintain the motor patterns of full song. However, many of these close-ended learners maintain plasticity in overall song organization; the number and the sequence of song elements included in a song of an individual vary from one utterance to another, although no new song elements are added or lost in adulthood. It is conceivable that these species rely on continued auditory feedback to produce normal song syntax. The Bengalese finch is a close-ended learner that produces considerably variable songs as an adult. In the present study, we found that Bengalese finches require real-time auditory feedback for motor control even after song learning is complete; deafening adult finches resulted in development of abnormal song syntax in as little as 5 days. We also found that there was considerable individual variation in the degree of song deterioration after deafening. The neural mechanisms underlying adult song production in different species of songbirds may be more diverse than has been traditionally considered. © 1997 John Wiley & Sons, Inc. J Neurobiol 33: 343–356, 1997     

Die Flechtenflora der Mödlinger Klause einst und jetzt (Niederösterreich)

Die Flechtenflora der Dolomit-Felshänge beiderseits der Mödlinger Klause ist in den Jahren 1856–1868 zum ersten und im Jahre 1984 ein zweites Mal erfaßSt worden. Sie hat sich in den rund 120 Jahren kaum verändert im Gegensatz zur Rindenflechtenflora, die nach Ausweis der alten Angaben und rezenter Beobachtungen stark verarmt ist und deutliche Zeichen von Schädigungen zeigt. Für das Gebiet der Klause sind an Flechten auf Dolomitgestein, sowie auf Erde und Moosen iiber Dolomit bisher 82 Taxa beobachtet worden, nicht eingerechnet die meist nur in fragmentarischen Individuen auftretende Gattung Collema, die meisten Verrucariaceen sowie einige schwer deutbare Namen der alten Literatur. Einige der 1984 aufgefundenen Flechten sind iiber das lokale Interesse hinaus bemerkenswert; Catillaria scotina und Dermatocarpon leptophyllum sind neu fiir die Alpen, Caloplaca atra ined. ist eine vermutlich unbeschriebene, ganz iiberwiegend sterile Art. Die Flechtenfloren von Kalk- und Dolomitgesteinen weichen nicht unwesentlich voneinander ab, wurden aber bisher zu wenig vergleichend studiert. Auf Dolomit treten Z. B. einige Arten auf, die sich sonst auf kalkarmen Silikaten finden.     

Altersabhängiges Lernen bei der Japanischen Wachtel (Coturnix coturnix japonica)1

The main question of our investigation is: Do there exist age-specific learning abilities in animals? 120 quails (Coturnix coturnix japonica) of 12 different age groups (between one day and 20 weeks) were tested in a combination apparatus by using two training methods. 60 quails were trained with decreasing (1), 60 other quails with increasing learning assistance (2). In each case the learning period lasted 5 days after which the animals were tested in a two-way choice apparatus and in a simple maze. Retention was tested 3 weeks later. -The 2 methods led to different results. In general the younger animals learnt better than the older ones when trained by method 1. No differences in learning performance between the 12 age groups were obtained by method 2.     

Richtungsbevorzugungen von Mönchsgrasmücken (Sylvia atricapilla) während der Herbstzugunruhe. Vergleich zweier Populationen mit verschiedenen Zugrichtungen

Directional Preferences of Autumnal Migratory Restlessness in Two Populations of Blackcaps (Sylvia atricapilla) with Different Migratory Directions The directional preferences in the orientation behavior of blackcaps, Sylvia atricapilla, were investigated. Two populations on different sides of the migratory divide were studied; one which flies in a SE direction in autumn and one which flies in a SW direction. The populations were from Lake Constance in the F.R.G. and Lake Neusiedl in Austria. Directional preference during fall migratory restlessness was determined by using Emlen funnels. The birds were hand-raised from the nestling phase on under identical conditions. The results demonstrated significant differences between the populations in the autumnal directional preferences. For SW migrants it was 240.7° and for SE migrants 185.0°. One can conclude from these results that there are population-specific differences in the innate directional preferences of fall migratory restlessness. A number of possibilities are discussed as causes for the extreme westward orientation of the birds from Lake Constance:

• 1 The WSW orientation of the Alps could be genetically programmed into the pattern of migration.
• 2 It could have been the result of a compensation for the transport from Lake Constance to Lake Neusiedl and therefore explained by goal area navigation.
• 3 Recently, there have been many reports of German blackcaps wintering in Holland, England and Ireland. It is possible that a number of the experimental birds had already chosen this direction and with their WNW preference, the overall preference is shifted westward.

     

Fehlermöglichkeiten der Gelöstsauerstoffmessung beim Betrieb von Bioreaktoren

A review of errors, which can influence the measured data of electrochemical oxygen sensors (OS) in fermentation technique is presented. The specifities of various sensor constructions are pointed out. References are given for selection of sensors to application in fermenters. Influences on the measured values can take place by fermentation conditions, arrangement of sensors in the fermenter and composition of the fermentation broth. The oxygen measurement in the multi-phase system of fermentation fluids can cause a remarkable deviation of the measured values to the real ones. Practical hints are given for use, calibration and sterilization of OS. Restricting conditions for measurements with this sensors are enumerated.     

Möglichkeiten der Gewinnung von Koppelprodukten der mikrobiellen Eiweißsynthese auf der Basis von Kohlenwasserstoffen

The mass production of SCP on the base of hydrocarbons opens the possibility to get a complex of further substances. It is distinguished between by-products – belonging to essential nonprotein – structures of the growing cell and the so – called coupled products accumulating intra – or extracellularly by means of regulation. An important principle of SCP-coupled synthesis of products is the use and the maintenance of proportionality between the growth rate and cell concentration of the producing cells and the accumulation of products. As examples are discussed: fermentation by yeasts and bacteria on the base of n-alkanes, methane and methanol in connection with products as fatty acids, poly-β-hydroxybutyric acid, citric and gluconic acid.