The impact roads have on the environment are well documented and gaining increasing attention world-wide. Aside from roads benefitting wildlife as habitat for plants or as corridors, they can also disrupt animal movements, eliminate and alienate their habitat, and represent a source of mortality. Furthermore, as roads are upgraded to accommodate greater traffic volume, the rate of successful wildlife crossing decreases significantly, becoming in some cases the leading cause of wildlife mortality. Attempts to reduce mortality and increase barrier permeability across road structures can be found in some road construction and upgrade projects. Presently there is limited information on the efficacy of wildlife crossing structures for large carnivores. Despite the obvious need for information on the effectiveness of highway mitigation measures such as wildlife crossing structures (underpasses and overpasses) and fencing for wildlife, most studies addressing this matter up until now have focused on ungulate species. Initiatives such as the TEA-21 bill in the USA and program COST-341 in the European Union have heightened the concern for sustainable transport systems and incorporating mitigation passages in transportation planning schemes. Decision-making by land managers and transportation planners regarding design requirements for effective structures is hampered by the dearth of information currently available. An intensive 5-year research program was initiated in Banff National Park (BNP) in November 1996 and was designed to address two main functions of roads that have major impacts on wildlife: mortality and habitat connectivity. This study focuses primarily on the Trans-Canada highway (TCH), its permeability for wildlife and effects in terms of wildlife mortality, movements, and habitat connectivity in the Bow River Valley. Means of mitigating road effects on wildlife are evaluated and recommendations will be made for future transportation planning schemes in the mountain parks. Herein we report on some of the results from the TCH mitigation research. (Author/publisher)
Samenvatting