Do Highways Influence Density of Land Birds?

/ Land bird densities in roadside habitats were studied in 17 locations in central Finland by the line transect method. Two transects were censused in each location. The first transect was situated 25 m from highway edge and the second transect 200 m away from the first one. The results suggested that land bird density was lower closer to highways. Species that avoided the road included willow warbler (Phylloscopus trochilus), crossbills (Loxia spp.), and tree pipit (Anthus trivialis). The composition of the bird community did not vary significantly between the compared transects. Some species appeared to favour road-forest edges but this could not be confirmed with our data. These species were not the same as have been reported to favor clear-fellings-mature forest edges. Therefore, the edge effect does not seem to be the most important factor controlling relative bird densities immediately adjacent and further away from highways. The likelihood of avoiding the problems the highways are causing for bird density are been discussed.KEY WORDS: Highways; Infrastructure; Bird density; Landscape ecology