Biophysical Features Determining Avian Use of Roadside Verges in Southern Québec's Suburban and Rural Landscapes

Habitat loss and degradation due to urbanization and intensification of agriculture are among the leading causes of the decline of biodiversity on Earth. Vegetated zones of rights-of-ways (the median zone and roadside verges) could, however, contribute to wildlife conservation where remaining natural habitats continue to rapidly disappear. The objective of this study is to identify biophysical features of the various maintenance units (green shoulders, embankments, ditches, and banks) of highway roadside verges (HRVs) in suburban and rural landscapes that influence avian abundance and richness. Results indicate that wider HRVs favor a greater use by birds, particularly when in association with an increase in the shrub cover in ditches and embankments. Since maximizing the contribution of the vegetated zones of the road network is now an important consideration in regional biodiversity conservation strategies in human-dominated landscapes, we recommend that embankments and banks should have a diversified plant structure and cover. Various changes to the conventional methods of the maintenance of vegetation along HRVs are therefore proposed, such as halting mowing for a period of 5 to 10 years to favor the succession of native plant species. Maximizing the contribution of HRV to bird conservation in suburban and rural landscapes will also have other environmental and social benefits.