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The test was carried out in the Central Poland, during the autumn migration in years 1997 and 1998, and the object was the Robin Erithacus rubecula. The aim of the study was the verification of the new field method for studying directional preferences in small Passerine migrants, proposed by Busse (1995). In total, 843 Robins were tested in "Busse's cage". Directions preferred by the tested birds were distributed in conformance with wintering areas and migration routes of the species known from literature. Robins with dark legs and grey plumage at flanks pointed at the directions according to the axis Scandinavia — the Balkans, which is in consistence with the literature data. Robins tested at daytime show stronger directionality than those tested at night. Birds tested with the sun visible expressed stronger directionality than those tested under overcast. The Robins tested at day more often pointed at the return direction — to the north and to the north-east. The activity of birds in the experimental cage increased at daytime with the lack of sun visible, and with overcast, and was higher in birds with smaller fat deposit, thus it reflected mainly the normal vital activity not associated with the migration.
Illustrated descriptions of Mosesia pavlovskii, M. sittae and M. microsoma have been presented. These species have been described for the first time in Poland, and two of them - M. sittae and M. microsoma - have not been know in Europe until now. Motacilla flava, Turdus philomelos and T. merula are new hosts of these trematodes. M. sittae has been recognized as an autochthonous species - completing its life cycle in the climatic conditions of Lower Silesia. As for the other two species, the author supposes that their invasion has been connected with the birds' migrations or wintering.
The level of maximum food energy intake or maximal existence metabolism (MPE) is 1.3 times higher in passerines than in non-passerines, which agrees with the ratio of their basal metabolic rates (BMR). The optimal ambient temperature for maximizing productive processes (e.g. reproduction, moult) is lower in passerines than in non-passerines, which allows passerines to have higher production rates at moderate ambient temperatures. This may explain variation in bioenergetic parameters along latitudinal gradients, such as the ecological rule of clutch size (or mass) increase in the northern passerine birds. The increased potential for productive energy output in the north may allow birds to r.ioult faster there, as well. This phenomenon allows passerine birds to occupy habitats of widely fluctuating ambient temperatures in comparison with non- passerine birds of similar size. Passerines have more effective system for maintenance of heat balance at both high and low temperatures. The high metabolism and small body sizes in passerines are consistent with development of omnivory and ecological plasticity. Among large passerines the unfavourable ratio of MPE to BMR should decrease energy available for productive processes. This limits both reproductive output and the development of long migration (especially in Corvus corax).
As a result of a survey of 362 birds, data were accumulated concerning the influence of migration and seasonal distribution of the Protozoa of the genus Plasmodium, Haemoproteus, Leucocytozoon and Lankesterella and Microfilariae. Material for study consisted of blood films which had been collected over two years. The smears were stained with Giemsa stain and each was examined approximately twenty minutes. The monthly incidence of infections is shown in Table 1. Plasmodium was found in 8.3 per cent of all atudied birds, from March to December with the highest intensity during the summer period. The non-migratory birds were infected in 81 per cent (of all infected with Plasmodium birds). Haemoproteus was established in 6.4 per cent from April to October. In majority this protozoan was found in migratory birds (70 per cent of all infected with Haemoproteus birds). The most popular in Poland are the protozoans of the genus Lankesterella and Leucocytozoon. These two genus were found in Poland through the all years. Leucocytozoon was found in 12.4 per cent. In majority this parasite was established in birds of the family Corvidae (78.5 per cent of all infected with Leucocytozoon birds). Corvus frugilegus was caught in majority in the winter period and it was infected in 57.7 per cent. It is interesting because the birds, which are in winter in Poland were coming from north and east. Microfilariae were found through the all year and 50 per cent of Corvidae were infected with this parasite.
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