Press Release


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Agencies Make Roads Safer for Wildlife and People

Many people probably have experienced the sinking and helpless feeling when their car's headlights encounter a set of motionless eyes reflecting back at them.

Most of the time, the driver's corrective maneuver successfully avoids the creature that seemed to come out of nowhere. But many times it does not.

The results usually include a damaged car and a dead or dying animal in the road. Worse, if the animal is a large deer, elk or moose, the result is often a wrecked vehicle with a potentially injured occupant.

It is hard to escape such a situation, considering the vast wildlife resources and miles of highway in Idaho.

Many other wildlife species less conspicuous than deer and elk also fall victim on Idaho's roads, including small mammals, reptiles and birds. Vehicles have overtaken hunting as the number one contributor to human-caused wildlife mortality. An estimated 200 humans are killed, and 29,000 injured, every year from deer-vehicle collisions. Researchers with the Western Transportation Institute at Montana State University estimate that the average costs of hitting an individual deer, elk or moose are $8,000, $17,500 and $28,600, respectively. These costs include the damaged vehicle, the loss of the animal for hunting and wildlife viewing, human injuries or fatalities and accident investigation. Greater than $1 billion in property damage results from wildlife-vehicle collisions every year in the United States.

Simply put, wildlife-vehicle collisions can be costly to wildlife and humans.

Highways can affect wildlife in other ways. Besides the loss of habitat when they are built, highways with high average daily traffic act as "virtual barriers" to wildlife movement, thereby restricting access to needed habitat.

Roads also fragment the landscape, making once suitable habitat ineffective.

Leading road ecologists from Harvard University say that roads have ecologically affected 15 to 20 percent of the United States. That translates to roughly 400 million acres out of 2.3 billion acres.

With the Idaho Transportation Department and Federal Highways Administration, Idaho Fish and Game has initiated two statewide projects to make highways safer for wildlife and people.

The first is to identify wildlife linkages in relation to state and federal highways. Wildlife linkages are areas where wildlife can find security to move between larger habitat blocks and where they can live at certain times of the year.

A classic example of a linkage area is a mule deer migration corridor.

Another example of a linkage area is the closest point where two mountain ranges come together. This is often a place larger animals, especially large carnivores, will use as a travel corridor from one mountain range to another.

When a highway bisects either one of these linkage areas, there is a tendency for more vehicle and wildlife collisions.

Identifying linkage areas is one of the first steps towards designing highways that are more wildlife friendly. Early in a project's planning stages, this information allows the Transportation Department to integrate wildlife-friendly transportation decisions in a more cost effective manner.

Idaho Fish and Game recently completed six day-long workshops to help identify wildlife linkage areas in relation to state and federal roads in southern and northern Idaho.

Using digital wildlife, habitat, and transportation maps, more than 200 biologists, engineers, and maintenance personnel - from Fish and Game, the Transportation Department, U.S. Forest Service, Bureau of Land Management, Federal Highways Administration, U.S. Fish and Wildlife Service, and several nongovernmental organizations - collectively identified about 500 individual linkage areas through out the state where wildlife and highway issues exist.

This information has been coupled with previously collected data from north-central and eastern Idaho, and incorporated into a statewide Geographic Information System for future transportation planning efforts.

In addition to transportation planning, linkage information can be used for other conservation purposes. Using the mule deer migration corridor as an example; severing the corridor, whether by expanding a two lane highway to four lanes, or converting once open space to a housing development, can disrupt the effectiveness of that linkage area.

Knowing where important wildlife linkages are means limited conservation resources can be focused on more informed conservation planning that will benefit wildlife.

The second project is to develop a statewide wildlife-vehicle collision database to gain additional information on where these problems are happening. The number of animals killed in vehicle collisions on Idaho highways is unknown, but on certain stretches of highway up to 10 mule deer per mile are documented being killed each year.

By combining wildlife-vehicle collision data with known wildlife linkage areas, the Transportation Department will have even greater knowledge of where highway and wildlife issues occur.

Transportation construction costs have risen in recent years while transportation funds have become scarcer, but by working together the agencies can balance the needs of wildlife with transportation in the most cost-effective manner possible.

This cooperative effort is an important step towards healthier wildlife populations and safer roads as the state's human population and transportation needs continue to grow.

For more information on these two projects, please visit the Idaho Fish and Game website at: