Table of Contents Executive Summary 2
Case Studies: Management Strategies
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- Germany
- The Netherlands
- The United States
- Site Assessment Metric
- Assessing Sites of Amphibian Mortality
- Inherent Limitations of Metrics
Case Studies: Management StrategiesSwitzerlandSwitzerland has a long history of research and action based on animal crossing. Swiss scientists have developed a Geographic Information System (GIS) that shows animal habitat and corridors where many animals travel across roads. In these places, the Swiss have adapted numerous methods for preventing animal collisions with cars. When the concern is only larger game like deer, they have constructed warning signs that can detect animal movement along roadside. When an animal moves across the motion detector the sign flashes on warning oncoming traffic that something is close to the road. Constructing large animal overpasses is another method used by the Swiss. Through many studies the Swiss have determined that the best overpass for animal use would have a minimum width of 50 meters (Bank, 2002). By incorporating vegetation and water, the overpass is like the natural environment (Figure 1). This method has proven successful with a wide variety of users from large game to small amphibians and insects. Overpasses are constructed with video cameras and tracking plots to measure their effectiveness. Tracking plots are built in the crossings and have either ink pads that dirty up the animals feet causing it to leave tracks, or fine sand pits that the animal must cross over. When crossed the fine sand will have imprints of the animal’s feet (Sauvajot 2002). W  hen the target animals are small mammals or amphibians an underpass may be used. There are many different methods for building underpasses but one that the Swiss have used is a one-way tunnel system. This system funnels amphibians from upland habitats to breeding sites in the spring and fall. The only way for the animal to cross the road is through the one-way viaduct, this lowers animal death and still allows the amphibians to reach their breeding ground without major difficulty. One major method the Swiss use to ensure the safety of animals at road crossing is teamwork between transportation and environmental planners. Without teamwork and concern for the animals not much can be accomplished (Sauvajot 2002).
GermanyGermany has gone in slightly a different direction when dealing with overpasses. They have created their overpasses to be used by more then just animals. They have created their overpasses to incorporate humans as well as animals. In farm areas, they have built overpasses with tractor trails as well as pathways for walking and biking. This method is beneficial to animals and the local communities. These overpasses not only connect habitat but also farmland. In addition, Germany has focused on underpasses that are built specifically to prevent noise pollution. Passing cars create noise that prevents s  ome animals from using the tunnels. By building tunnels deeper under the road, it cuts down on some of the noise pollution. In Figure 2, the underpass is built just under the road’s surface. This underpass does not sufficiently cut down on noise. Different types of fences can also be used to cut down on the noise near roads (Hagood, 2002).
The NetherlandsThe Netherlands has used similar methods as the other countries. Overpasses are built for all types of animals, from large mammals to small insects and many underpasses have been built for small mammals and amphibians. In their underpasses they have built in wood or earth shelves that are built for mammals to cross in watery culverts. In all, the Netherlands have approximately 600 culverts, with only ten built specifically for amphibians (Gray, 2002). The United StatesThe United States has come a long way since concern over wildlife began around roadways. Many states have begun planning and building crossings. Florida for example, has already created many amphibian crossing areas. They have progressed faster then most of the other states and they have an extensive system of crossing culverts. In one two mile stretch on Route 441 in Florida, they have built a 3 1/5 foot high concrete wall with a 6 inch lip at the top (as seen in Figure 3) that directs reptiles and amphibians along the road to an underpass (Southall, 2000). This wall prevents animals from climbing to the roads and it has been a success. 
Concern throughout the United States has been growing and something must soon be done. Many planning committees have used the methods discovered and implemented in Europe. There is no one solution, each situation is separate and can be handled differently. The future for animal crossings here in the United States looks promising. As long as there is public concern, animals will be protected. Site Assessment MetricThe Purpose of a MetricFrom measuring the success and excellence of businesses, to quantifying a range of ecological factors, metrics can be used for a multitude of useful applications. In recent years, they have been used to assess biodiversity, degrees of environmental degradation (Sutter 1992), population dynamics, and habitat suitability (Mitch and Gosselink 2000). Indeed, metrics, also often referred to as indices, can be used to evaluate largely anything that a scientist might desire to study. In the environmental field, the use of metrics has proven to be a successful method for quantifying otherwise subjective environmental factors. Assessing Sites of Amphibian MortalityThe development of a metric is a somewhat arbitrary practice. However, in this instance a metric is simply a useful by-product of a landscape/habitat assessment. VTRANS, the state of Vermont’s transportation department, has expressed a desire to implement a program designed to prevent amphibian mortality due to road crossings. Each year, large quantities of amphibians are flattened by passing cars, which presents both environmental and safety problems. VTRANS has experimented with small-scale structures designed to prevent amphibians from crossing state highways, however, they are interested in more permanent solutions to a problem they anticipate will otherwise be long-term. Inherent Limitations of MetricsAs is true with any metric, there will be flaws inherent to the final product, most often related to incomplete, insufficient, or inaccurate data. Please refer to the “Recommendations for Further Research” section of this paper for information on missing data related to our metric. In any instance, it is recommended that any necessary, or otherwise helpful, data be obtained as soon as possible in order to facilitate the further development of the metric. Lack of funding may preclude extensive data collection, although the hiring of college interns or other relatively inexpensive help could assist in making the data collection possible. Download 181.31 Kb. Share with your friends:
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