Modern forestry may alter avian reproductive success indirectly through affecting predator-prey interactions. Here we evaluate the influence of road types on nest predation of ground-nesting birds in a highly fragmented forest area interspersed by a dense network of roads and forest paths, with one third of the area covered by a red-deer enclosure. Experimental nests (n = 276) resembling black grouse ( Tetrao tetrix) nests were proportionally installed along three types of roads discriminated by utility (road type, from frequently used to unused: tarred roads, gravel roads and forest paths) and inside/outside the red-deer enclosure. The nests were placed in couples, with one nest placed close to the road edge and the second placed inside the surrounding forest habitat to assess the “travel line” hypothesis. The “travel line” hypothesis was not supported because there was a similar predation rate among edge and interior nests. Even if predators can be discouraged along busy roads, type of road also did not affect nest predation. Nevertheless, nest predation inside the enclosure was significantly lower than in the surrounding, suggesting that frequent human disturbances in these habitats may have a repellent effect on predators of ground nests.
A mathematical model of the roadway automobile motion is numerically analyzed. This model is intended to describe the roadway automobile stability. A previous paper [6] described the model in detail and the general method of qualitative analysis. In the present paper, we continue the discussion of stability by numerical simulations and the specific question we attempted to answer is: which parameter(s) of automobile geometry and quality of the roadway can serve as a reliable predictors) for car crash? Data from Daimler-Chrysler AG and Ford Motor Company Limited were used for that purpose, considering three car types - Mercedes-Benz E 320 (T-modelle), Ford Focus and Mercedes-Benz Sprinter (1). Hence, one can consider the present work as a natural continuation of [6]., Obsahuje seznam literatury, and Článek doplňuje Appendix na str. 294-295
J.B. Singelée* Jean-Baptiste Singelée, G. Meyerbeer* Giacomo Meyerbeer, and [neu revidiert und mit Fingersatz versehen von Henri Petri* Henri Wilhelm Petri]