The feeding area selection of the common crane was studied between 1996–1998 in the Hortobágy National Park and surrounding areas during the autumn migration and staging over period. The cranes roosted in marshlands and drained fishponds and fed in the following types of agricultural areas: maize stubble, maize-, wheat-, alfalfa-, and abandoned fields as well as natural grasslands. The largest proportion of crane flocks fed on maize stubbles on waste grain. Family flocks usually fed separately. The type of feeding area did not depend on the time of the day. The density of feeding flocks did not depend on the type of feeding area, indicating high abundance of food. The study suggests that agricultural areas inside the National Park should be used for growing maize for staging cranes in order to attract them from disturbed non-protected arable lands outside the National Park. It is also important to stop wildfowl-hunting in fishponds to let cranes choose between more roost sites closer to feeding areas.
Diet, carcass weight (dressed weight) and kidney fat index (KFI) in wild boar populations were compared between two different lowland environments in south-western Poland. In the forest-farmland environment of the Lasy Śląskie forest (LS), fodder root crops and cereals made up 67.6 % of the dry weight (d.w.) of stomach content (n = 40). In the large compact forest of the Bory Dolnośląskie forest (BD), 69.6 % of the stomach content (n = 43) was made up of roots and browse. Piglets and older animals harvested in BD were significantly lighter than those harvested in LS (13.6 kg vs. 25.6 kg and 47.3 kg vs. 55.9 kg respectively). The KFI of piglets and older animals harvested in LS were significantly higher than those incorresponding age classes of wild boars from BD. The metabolized energy of stomach content amounted to 13.2 MJ/kg d.w. in LS and 8.9 MJ/kg d.w. in BD. This is probably the chief cause of the differences in carcass weight and KFI between the wild boars living in the compared study areas.
Habitat use of introduced pumpkinseed Lepomis gibbosus in small European streams has received little study despite the species’ potential associations to native fauna of conservation and angling amenity, e.g. brook lamprey Lampetra planeri, European bullhead Cottus gobio, brown trout Salmo trutta. We examined body size, relative body condition, habitat use and species-species associations of pumpkinseed with accompanying fishes in two small streams in southern England during August 2001. Pumpkinseed body condition decreased with pumpkinseed density; the latter correlated with % clay and % riparian grasses in fish 92 mm FL. Most pumpkinseed size classes occurred more often than expected in stretches with conspecifics and with brown trout >300 mm FL; densities of the latter did not correlate with any habitat variables. Indeed, correlations between trout densities and habitat variables were observed mainly in smaller size classes. Habitat associations in other species corresponded to known levels of rheophily; substratum, channel slope, channel width and riparian trees were also important habitat variables. Pumpkinseed dispersal and establishment under conditions of climatic change, which could have ecological and management ramifications, are discussed.
Basic methods of the sensitivity analysis applicable in combination with numerical Monte Carlo type simulation methods are presented in the paper. An example of the influence of a plane steel fame initial imperfections on its load-carrying capacity variability is given there. It is shown in this paper that basic sensitivity analysis methods can be inaccurate in some cases. The updated modification of the procedures mentioned is proposed so that it were possible to apply them to the most various structure types solved by means of simulation methods. The influence of initial imperfections on the load-carrying capacity of steel plane frame is analysed by auxiliary sensitivity analysis. The realisations of input random quantities were simulated by the Latin Hypercube Sampling method. The load-carrying capacity was solved by geometrically and materially nonlinear solution. and Obsahuje seznam literatury
In this paper, we prove and discuss averaging results for ordinary differential equations perturbed by a small parameter. The conditions we assume on the right-hand sides of the equations under which our averaging results are stated are more general than those considered in the literature. Indeed, often it is assumed that the right-hand sides of the equations are uniformly bounded and a Lipschitz condition is imposed on them. Sometimes this last condition is relaxed to the uniform continuity in the second variable uniformly with respect to the first one. In our results, we assume only that the right-hand sides of the equations are bounded by some locally Lebesgue integrable functions with the property that their indefinite integrals satisfy a Lipschitz-type condition. Also, we consider that they are only continuous in the second variable uniformly with respect to the first one.