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71.
Markus Jenny 《Journal of Ornithology》1990,131(3):241-265
Zusammenfassung In einer intensiv landwirtschaftlich genutzten Fläche des schweizerischen Mittellandes wurden 1983–1987 vier Feldlerchenaggregationen mit maximal 39 Brutpaaren untersucht. Die Tradition (Ortstreue) bestimmte in erster Linie die Revierwahl und das Verteilungsmuster. Die Reviere waren mit
ha sehr groß; ihre Größe korrelierte negativ mit der Anzahl Parzellen pro Fläche und der Kulturendiversität. Die Nutzung des Ressourcenangebots (Nistplatz, Nahrung, Schutz) war abhängig von den Fortbewegungsmöglichkeiten. In großparzellig strukturierten Flächen mit geringer Kulturendiversität kam es häufig zu Revierverschiebungen und Reviervergrößerungen. Die Feldlerche versucht, im Laufe der Brutperiode den Getreideanteil im Revier zu verkleinern und Kulturen wie Rüben, Kartoffeln und auch Mais zu aquirieren. Die Nistplatzwahl zeigte eine deutliche Präferenz für alle nicht zu dicht stehenden, grasartigen Kulturen (Weizen, Hafer, Fettwiese). Eine Vegetationshöhe von 15–25 cm und eine Bodenbedeckung von 20–50 % bieten optimale Bedingungen für den Nestbau. 51 % aller Nester wurden in der Fettwiese angelegt, 20 % im Winterweizen und 18 % im Mais. Je nach Bewirtschaftungsart brüteten die im Mittel 2,4–2,8mal pro Brutsaison. Die Schlüpfrate von 220 Gelegen betrug 0,58. 44 % der geschlüpften Jungvögel verließen das Nest. Der Bruterfolg (nestverlassende Junge/gelegte Eier) lag bei max. 25 %. Dem Fütterungsverhalten der Altvögel nach zu schließen, wurden maximal 50 % der nestverlassenden Jungen flügge. Durchschnittlich war mit 0,9 flüggen Jungen pro Brutpaar und Jahr zu rechnen. Brutverluste waren kulturspezifisch und daher in erster Linie vom Neststandort abhängig.
Territoriality and breeding biology of Skylark (Alauda arvensis) in an intensively farmed area in Switzerland
Summary In 1983–1987 four plots (total surface 307 ha) with up to 39 breeding pairs were studied in an area of intensive cultivation in the Swiss Lowlands (390 m asl). Distribution pattern and selection of territories are determined by a strong site tenacity of the birds. The size of territories averaged 3,3±0,9 hectares. It correlates negatively with the number of different crops per unit area and the diversity of cultures.The mobility within the vegetation determined which types of farmland ressources may be used for nesting, feeding and cover. Shifts of territories and attempts to enlarge them were frequent in areas of large plots with low crop diversity. During the season, Skylarks tried to reduce the proportion of cereal fields within their territory and to gain plots planted with sugar-beet, potatoes and corn.Their choice of nesting sites showed a strong preference for less dense grass crops such as wheat, oat or meadows. Optimal conditions for nest sites were in fields with a vegetation height of 15–25 cm and a ground coverage of 20–50 %. 51 % of 220 nests were constructed in heavily manured meadows, 20 % in winter wheat fields and 18 % in corn fields. Females bred on average 2,4–2,8 times per breeding season, depending on the type of cultivation (agriculture, husbandry). Hatching rate was 58 % out of 220 clutches, and 44 % of the hatched young left the nest. Maximum breeding success (i. e. young birds leaving the nest/number of eggs laid) was thus maximal 25 %. Observations of parental feeding behaviour suggest that a maximum of 50 % of the young larks which leave the nests survive to the age of fledging. It is estimated that 0,9 fledglings are raised per breeding pairs and year. Losses of broods vary according to farming practises in the different crops and therefore are largely depending on nesting sites.相似文献
72.
Gerhard Toggenburger Max H?sermann Beat Mütsch Giulio Genoni Markus Kessler Fritz Weber Dietrich Hornig Brigitte ONeill Giorgio Semenza 《生物化学与生物物理学报:生物膜》1981,646(3):433-443
l-Ascorbate is taken up into brush border vesicles from kidney cortex of rat, rabbit and guinea pig by an efficient, Na+-dependent and potential-sensitive transport process. This uptake shows saturation () and is strongly stimulated by low concentrations of N3?. Erythorbate (d-isoascorbate) seems to be another, but poorer, substrate of the same transporter. 相似文献
73.
Pseudomonas sp. strain CBS3 was able to utilize 4-chlorophenylacetic acid as the sole source of carbon and energy. When this strain was grown with 4-chlorophenylacetic acid, homoprotocatechuic acid was found to be an intermediate which was further metabolized by the meta-cleavage pathway. Furthermore, three isomers of chlorohydroxyphenylacetic acid, two of them identified as 3-chloro-4-hydroxyphenylacetic acid and 4-chloro-3-hydroxyphenylacetic acid, were isolated from the culture medium. 4-Hydroxyphenylacetic acid was catabolized in a different manner by the glutathione-dependent homogentisate pathway. Degradation enzymes of both of these pathways were inducible. 相似文献
74.
75.
Hanno Würbel Markus Stauffacher Dietrich von Holst 《Ethology : formerly Zeitschrift fur Tierpsychologie》1996,102(3):371-385
The ontogeny of two stereotypic patterns, wire-gnawing and jumping, was studied in 24 laboratory mice: six males and six females each of two closely related outbred strains, kept under standard housing conditions, a conventional albino strain (ICR) and a nude, athymic mutant (ICR nu; hereafter: NU). All 24 individuals developed wire-gnawing after weaning at 20 d of age. In ICR one female and in NU five males and three females additionally developed jumping. ICR developed wire-gnawing between the age of 20 and 30 d, in NU jumping started at the age of 20 d, but intense jumping and wire-gnawing comparable to that of ICR did not develop in NU before the age of 40–50 d. Within each strain there was no significant difference between males and females with respect to the development of stereotypic behaviour. By contrast, ICR showed significantly more wire-gnawing but less jumping than NU. Stereotypy level increased with age up to a mean of 10.7 % of total activity in ICR and up to 7.4 % in NU at 100 d of age. However, there was huge inter- and intra-individual variability with respect to all parameters assessed in this study, i.e. total duration, number of bouts and bout length of the two stereotyped patterns. Wire-gnawing developed from outside-directed explorative climbing at the cage lid, whereas the source behaviour pattern (Mason 1991 a, Anim. Behav. 41, 1015–1037) of jumping was outside-directed explorative rearing at the cage wall. At 20 d of age, before the onset of stereotypy development, ICR showed significantly more climbing but less rearing than NU. Physical retardation of NU at weaning may account for decreased climbing ability during early ontogeny, and hence for the retarded development of wire-gnawing. The difference in early experience with either of the two patterns rather than genetic effects may be responsible for the qualitative difference between the strains with respect to the form of later stereotypy. 相似文献
76.
77.
Miles B Markus 《BMJ (Clinical research ed.)》1985,290(6481):1592
78.
Organisms in the wild are constantly faced with a wide range of environmental variability, such as fluctuation in food availability. Poor nutritional conditions influence life-histories via individual resource allocation patterns, and trade-offs between competing traits. In this study, we assessed the influence of food restriction during development on the energetically expensive traits flight metabolic rate (proxy of dispersal ability), encapsulation rate (proxy of immune defence), and lifespan using the Glanville fritillary butterfly, Melitaea cinxia, as a model organism. Additionally, we examined the direct costs of flight on individual immune function, and whether those costs increase under restricted environmental conditions. We found that nutritional restriction during development enhanced adult encapsulations rate, but reduced both resting and flight metabolic rates. However, at the individual level metabolic rates were not associated with encapsulation rate. Interestingly, individuals that were forced to fly prior to the immune assays had higher encapsulation rates than individuals that had not flown, suggesting that flying itself enhances immune response. Finally, in the control group encapsulation rate correlated positively with lifespan, whereas in the nutritional restriction group there was no relationship between these traits, suggesting that the association between encapsulation rate on adult lifespan was condition-dependent. Thus stressful events during both larval development (food limitation) and adulthood (forced flight) induce increased immune response in the adult butterflies, which may allow individuals to cope with stressful events later on in life. 相似文献
79.
80.