Roads are a threat to biological diversity. Especially the hazel dormouse (Muscardinus avellanarius) can be badly influenced by fragmentation due to its strictly arboreal activity. In this study a Northern German dormouse population living in roadside habitats and on road islands at crossroads was investigated to find out if road crossing is an exceptional behaviour or if it happens regularly. With capture-mark-recapture-method 30 crossings (mostly across a federal highway, three of them across a federal motorway) and via telemetry 27 crossings over federal highway and smaller streets were observed. Our study gives evidence, that road crossing can be a relatively frequent behaviour, as 18 % of the mark-recaptured and 60 % of the radio marked animals crossed roads, but it remains unclear, under which circumstances road crossing takes place.
Spring and summer composition and species richness of bruchid pre-dispersal seed predator assemblages associated with species of leguminous plants were monitored in a four-year non-experimental survey of 32 service areas along five highways in Hungary. The vegetation bands along highways (delimited by fences) were considered a special type of ecotone where herbaceous plants are exposed to regular mowing and therefore the composition of the vegetation there is very different from the adjacent vegetation. Altogether 57 herbaceous and woody species of leguminous plants were recorded at these sites, harbouring 20 autochthonous, 3 allochthonous, but established, and 4 recently introduced species of bruchid seed predators (Coleoptera: Chrysomelidae: Bruchinae). The species of leguminous plants recorded along highway verges during this project make up approximately one fourth of the Fabaceae in Hungary and of the bruchids ca. 80 % (!) of the species known to occur in Hungary. At half of the service areas, mowing decreased the species richness of leguminous plants compared to that recorded prior to mowing, but not that of their bruchid seed predators. However, the species composition of the bruchid assemblages before and after mowing changed substantially. Null-model analyses indicated a random organization of spring assemblages and a deterministic one of summer assemblages of bruchids; very likely a result of host-specificity constraints. Calculations of host specificity confirmed the narrow host range recorded for bruchids that emerged from the samples of plants, in spite of new host records, such as three and two Trifolium species for Bruchidius picipes and Bi. sp. prope varius sensu Anton, respectively, Oxytropis pilosa for Bi. marginalis and Vicia cracca for Bruchus brachialis. Our results show that a surprisingly high number of species of bruchids occur in highway margins, however, the management of the vegetation there prevents a substantial portion of the native bruchid fauna establishing permanent populations.