North American highways are playing havoc with wildlife populations.

How to cut down on....
Death Race 2000
by Peter Jekel

HighGrader Magazine January/February 2001
Canadians like to think of themselves as being very different from their American cousins. There may be some differences, but the love of the automobile is one thing that we share in common. Our governments are very aware of this love affair. Not since Sir John A. MacDonald pounded the last spike, has any government put as much effort and money into mass transit as they have into the roadways that crisscross our landscape.
In Ontario, the Tories have made it no secret that they are not friendly to mass transit. While provincial subsidies to mass transit were killed off, enormous amounts of money have been poured into the building of expanded highways.
Voters have supported these initiatives, but few have given any thought to the impact of highway expansions on animal life. As the landscape of the country is chopped up into neat parcels with corridors of fast-moving traffic, the impact on animal populations can be immense.
The only time Canadians notice these impacts is with the threat of collisions with larger animals like deer and moose. It has been estimated that the energy involved in the collision with a moose is the same as that of colliding with a second vehicle. So far, the most Ontario has done to limit these collisions is to post deer and moose crossing signs. Unfortunately, few drivers heed these signs.
But what about the toll taken on smaller animals? The sight of "roadkill" is all too familiar on Canadian roads. All too often, small animals are killed without the driver even noticing.
Road kills account for a significant number of deaths in leopard frogs, particularly in the spring and fall when frogs are on the move from wintering to breeding sites.
In fact, researchers at the Savannah River Ecology Laboratory at the University of Georgia have stated that roadkills have caused a significant decline in reptiles worldwide.
In Europe, a study concluded that there was a significant genetic difference between the population of voles on the one side of a four-lane highway as opposed to the other. The long term impact of isolating animals onto small parcels of land may have an impact on the genetic diversity of the animal population. It could help lead to the extinction of some species. Road construction, in other words, fragments the natural landscape and threatens all wildlife that must brave the trek across a roadway.

What is contributing to the gradual increase in highway carnage? Higher speeds are the main cause. Road construction (though some drivers, especially in the north, may dispute this finding) has improved the condition of our roadways which, in turn, allows vehicles to travel faster.
Another major problem is the increasing volume of highway traffic.
In Southern Ontario, the spread of the suburbs and the increasing distances travelled by commuters has lead to higher volumes of car traffic. Increased traffic equals increased highway carnage.
Another major factor is that improved headlight technology has allowed drivers to drive faster at night.
The most obvious solution for cutting down on the number of animals being killed is for governments to make a larger commitment to mass transit. Cutting down on the traffic volumes is the most effective way to cut down on the mortality rates of various species.
Recognizing that this solution is not likely to be adopted, the other choice would be to strengthen the environmental assessments being conducted prior to highway construction.
There is technology available that addresses the issue of animal-automobile encounters. However, the commitment and the money to implement it must also be there.

The Assessment Process
The first step is to identify where there are potential problems for wildlife-automobile encounters. In the State of Washington, the Department of Transportation instituted a study of the effects of a 30 mile stretch of I-90. They used GIS technology to assess habitat connectivity and animal distribution along the highway. They also used off-road automatic cameras to identify animals along the highways as well as monitoring bridges and culverts to see which animals utilized these structures to cross the highways.
Researchers in the University of Florida's Landscape Ecology Program have developed a GIS computer model that captures, manipulates, displays and combines the spatial information such as water courses, land uses, species distribution and existing roadways and greenways. The model is used by the Florida Department of Transportation to identify road-kill hot spots.
They can then adapt existing crossing structures or build new ones.

Artificial Structures
There is one stretch of Canadian highway that has addressed the issue of wildlife-automobile collisions. Up to 20,000 vehicles a day pass across the stretch of Trans-Canada highway that runs through Banff National Park at the height of the summer tourist season.
When 28 miles of the highway were widened between the east gate of Banff and Castle Junction, parks and transportation experts put their minds together to come up with ideas on how to reduce the increased risk of wildlife-automobile interactions.
Parks Canada first constructed a 8 foot high fence on both sides of the highway and built 22 underpasses (Culverts of all sorts and sizes) and two 164 foot wide overpasses. The result was a 96% reduction in highway kills.
The locations of the linkages were based on natural travelways such as stream corridors and drainage areas for carnivores. Other pathways for ungulates were developed far from the carnivore structures.
Ungulates also needed a clear sight of the structure in order for them to utilize them. There is still work to be done, however, as black bears and cougars are not adverse to climbing the fences.
One way to control this would be to increase meshing at the top of the fence. Another is to eliminate the dandelions at the side of the highway which attract the black bears.
The more practical method is to limit human activity at the crossing structures since large carnivores like to be as far from humans as possible.

The State of Florida has created an underpass for black bears along a stretch of State Route 46. A similar underpass was also built for Florida panthers along I-75. The State Route 46 underpass was built to be bear-friendly with a dirt floor, 24 feet wide and 8 feet high. The construction workers also raised the two lane road over the crossing so that the animals could have a clear view of the other side. Rows of pines in the open pasture on one side of the road guided the bears to the entrance.
As an added bonus, not only did bears use the link but so did twelve other species as well.
Florida has also built the first land bridge. It was just completed in the summer of 2000. It is in a strip of Marjorie Harris-Carr Cross Florida Greenway that crosses 1-75 north of County Road 484 in Arion County. Animals will pass over the highway through native vegetation and sandy soil that they are used to.
Humans, too, can use the passage to cross the highway. The bridge also sports a built-in irrigation system and 18 foot high planters on both sides, thereby making it attractive to the 50,000 drivers who approach the overpass everyday.
Florida has also worked to deal with smaller animals crossing roadways. One stretch of US 441 in Florida had the highest number of roadkills in the state. It is a short two mile stretch that crosses Paynes Prairie State Preserve outside Gainesville. The animal deaths are mostly reptiles and amphibians trying to cross the road.
In 1997 the Paynes Prairie Working Group was formed to address this roadkill problem. The result was a 2.5 foot high concrete wall that diverted wildlife to 8 underpasses. The wall had an additional 6 inch lip at the top to deter climbing reptiles.

Salamanders Get Smushed
Near Amherst, Massachusetts, the spring rains bring out the salamanders which try to cross a two lane section of road called Henry Street. The reason is that Henry Street bisects some warm, fishless ponds where the salamanders lay their eggs. When the rains and outside temperature signal to the salamanders that these temporary ponds are ready for their eggs, the trek begins. And so does the carnage.
The plight of the poor creatures hasn't gone unnoticed. Groups as far away as the British Fauna and Floral Preservation Society and the ACO Polymer of Germany provided funds for an experimental tunnel project on Henry Street. The Amherst Department of Public Works, Massachusetts Audubon Society and local conservation groups worked together to make it happen. In 1987, two tunnels were built - 200 feet apart at the crossing sites with drift fences to guide the salamanders to the tunnels.
Again as we have seen with other animal crossing technology, the tunnels had to be salamander-friendly. Each tunnel was slotted to permit light entry and provided the damp conditions that salamanders need. Subsequent studies showed that up to 75% of the salamanders used the tunnels.

The Tortoise and the Hare
Another region in that has started to address animal carnage is the State of California. A high death rate of tortoises was noticed along state Highway 58 which runs through San Bernardino County on Mojave Desert land. Eight federal and State agencies put their resources together to monitor the effectiveness of the use of existing storm drain culverts by tortoises. Tortoises are slow moving and do not move along set patterns or routes, so that tracking them is important when deciding how well they are utilizing a structure.
The solution was the Passive Integrated Transponder which is primarily used to census fish but was adapted to use on desert tortoises. When a tortoise entered or left the culvert, it passed through an electromagnetic field emitted from a reader that was tuned to a specific radio frequency.
It is hoped that the initial lack of success of tortoises using the corridors will increase with experience. It is a system that can be adapted to other animals.
What about fish? Are they affected by roads? Apparently, and as a result Washington State Department of Transportation and the Washington Department of Fish and Wildlife are working together to identify, prioritize and remove barriers in culverts under state roads.
Fish such as salmon are most affected by culvert barriers since they must swim upstream to get to their breeding grounds.
The program began in 1991 and has found that of 4483 sites, 500 had potential problems. Some of the culverts indicated a situation that the water depth is too shallow, the water velocity too great or outfall drop too high. Engineers began to fix the culvert barriers by using a Priority Index System that ranks projects on potential habitat gains. Oregon, too, has stepped into the issue of barriers to fish passage and began to correct problem areas in their culvert systems.
How to deal with animals that burrow under directing fences? One innovation comes from Holland where until the 1990s, 20% of the country's badger population was killed annually.
Fences were constructed but the badgers simply dug under them. Near the Town of Heuman, the National Ministry of Transport constructed five tunnels under the highway and built higher, stronger fences to discourage badgers from climbing over or digging under.
Escape gates were even put in the fences at one kilometer intervals to protect any badgers that ended up on the road. The work also included a green belt linking the badger tunnels. It was found to be so successful that it is now a standard building procedure for every new highway project.
The question facing Canadians is how much are we willing to do to minimize our impact on nature? Certainly, the cost of road construction will increase if we factor in animal impacts.
But it is becoming clear that building highways with no consideration for the ecosystem is only doing half the job.

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