Passages for badgers and their efficacy

During the past decades the percentage of badgers falling victim to traffic accidents in the Netherlands had rapidly climbed to over 12% annually by the early 1990's (Tab. 1). Along with other endangering factors this loss was seen as a threat to the survival of the badger population. An important measure to reduce the number of traffic victims was the construction of badger passages (Figs. 1-3) together with the fencing of roads along these passages (Fig. 4). Free land observations showed that these pipes with a diameter of 30-40 cm were still attractive to badgers even if their lengths exceeded 100 m. Controls showed that the effectiveness of these passages was highly dependent upon the quality and the length of the adjacent fencing. The proper construction and careful maintenance of the passages and especially the fences are prerequisites for their efficacy. Despite the construction of more than two hundred passages the numbers of badgers killed in traffic accidents increased annually by more than 12% during the first half of this decade. On the other hand the badger population has also increased although a quantitative determination of this increase is still lacking. Hence, an evaluation of whether the construction of badger passages and adjacent fencing led to a decrease in the percentage of badgers killed by vehicles is not possible. The passages are also used by foxes, cars, (stone)martens polecats, weasel, minks, hedgehogs, rabbits and various species of mice.