Help us establish Louisiana’s First Wildlife Crossing
On Louisiana Highway 90 (LA 90) near Calumet, there exists an area where bears are routinely hit by vehicles. Large animals like bears and deer dart out on to the road from dense brush catching drivers by surprise. In 2009, this stretch of highway saw over 25 bear/vehicular collisions. Not only is this a needless loss of wildlife but hitting a bear can be fatal to drivers.
The BBCC supports a wildlife crossing at this juncture. The crossing would connect habitat and reduce the number of bear/vehicular encounters.
The proposed LA 90 crossing would be a slightly elevated portion of the highway with just enough height to allow animals to pass underneath.
This construction would be the first such wildlife crossing project in the state and as such, has not yet received the prompt attention it deserves. The DOTD (Department of Transport and Development) will address a wildlife crossing if land on both sides of the highway is protected in perpetuity as public land or servitude protected. It is a wet area and unsuitable for agriculture which helps matters. The land is privately owned so BBCC (Black Bear Conservation Coalition) is working to use monies from the CFCI (Coastal Forest Conservation Initiative) to fund either a purchase by the DNR (Louisiana Department of Natural Resources) or a perpetual servitude, thereby making the land comply with the DOTD specifications.
The delay is with DNR which has not yet responded regarding final guidelines for the CFCI program.
Costs and benefits
The benefits derived from constructing wildlife crossings to extend wildlife migration corridors over and under major roads appear to outweigh the costs of construction and maintenance. One study estimates that adding wildlife crossings to a road project is only a 7-8% increase in the total cost of the project. Theoretically, the monetary costs associated with constructing and maintaining wildlife crossings are trumped by the benefits associated with protecting wildlife populations, reducing property damage to vehicles, and saving the lives of drivers and passengers by reducing the number of wildlife-vehicle collisions.
Habitat fragmentation occurs when human-made barriers such as roads, railroads, canals, power lines, and oil pipelines penetrate and divide wildlife habitat. Of these, roads have the most widespread and detrimental impacts. Scientists estimate that the system of roads in the United States impacts the ecology of at least one-fifth of the land area of the country. For many years ecologists and conservationists have documented the adverse relationship between roads and wildlife by (1) decreasing habitat amount and quality, (2) increasing mortality due to wildlife-vehicle collisions (road kill), (3) preventing access to resources on the other side of the road, and (4) subdividing wildlife populations into smaller and more vulnerable sub-populations. Habitat fragmentation can lead to extinction if a population’s gene pool is restricted enough. One study found that roads contribute more to fragmentation in forest habitats than clear cuts. Another study concluded that road fragmentation of formerly contiguous forest in eastern North America is the primary cause for the decline of forest bird species and has also significantly harmed small mammals, insects, and reptiles in the United States.
The first wildlife crossings were constructed in France during the 1950’s. European countries including the Netherlands, Switzerland, Germany, and France have been using various crossing structures to reduce the conflict between wildlife and roads for several decades and use a variety of overpasses and underpasses to protect amphibians, badgers, ungulates, invertebrates, and other small mammals.
In addition to Western Europe, wildlife crossings are becoming increasingly common in Canada and the United States. The most recognizable wildlife crossings in the world are found in Banff National Park in Alberta, where vegetated overpasses provide safe passage over the Trans-Canada Highway for bears, moose, deer, wolves, elk, and many other species. Thousands of wildlife crossings have been built in the past 30 years to protect mountain goats in Montana, spotted salamanders in Massachusetts, bighorn sheep in Colorado, desert tortoises in California, and endangered panthers in Florida.