Crossing results show promise
June 6, 2017
Early returns from the Colorado Highway 9 Wildlife Crossing Project suggest that the recently installed animal crossings are working exceptionally well thus far, leading to a reduction in vehicle-wildlife collisions and potentially saving lives.
The project included two wildlife overpasses and five wildlife underpasses stretched out over 10.4 miles of Highway 9, between mile markers 127 and 137. It stretches between Kremmling and Green Mountain Reservoir. The project was completed in two parts, with the northern section in November 2015 and the southern in November 2016, and is meant to address the number of wildlife-vehicle collisions in the area, primarily with mule deer.
"Wildlife cross the highway multiple times a day, especially through the winter months, and we see that reflected in the number of animals that were hit on the road each year," said Julia Kitsch, principal and conservation ecologist for ECO-resolutions LLC, a company helping to monitor the crossings. "This is a serious issue for wildlife populations, but also for the community around Kremmling, which rallied in support of this project."
Data only currently exists for the northern portion of the project area, while data gathering continues on the southern portion. Early statistics show promising numbers, based on data collected from ECO-resolutions.
“This is a serious issue for wildlife populations, but also for the community around Kremmling, which rallied in support of this project.” - Julia Kitsch, ecologist
The first monitoring period for the northern structure collected crossing data from Dec. 7, 2015 through March 31, 2016. In that period, over 7,000 mule deer were recorded using the crossings, with a success rate of over 80 percent. Success rate is measured by animals' response to the new structures and whether or not they are willing to cross. The goal is to achieve a minimum 60 percent success rate, and 80 percent success by the final year of the study in 2019-20.
The most commonly used crossing is the north overpass at mile marker 134, which has seen over 4,800 successful movements from both sides of the road, and boasts a 98 percent success rate.
On the north section, where data has been collected, there were only three wildlife-vehicle collisions in the winter of 2015-16, down from a five-year average of 31 in the area during the winter months. That equals a 90 percent reduction.
"Mule deer, in particular, have been quick to adapt to using the new wildlife crossings — learning where the structures are and teaching their young," said Kitsch. "All of these crossing are potential collisions that have been avoided."
Monitoring the area is a combination of Colorado Department of Transportation, Colorado Parks and Wildlife and ECO-resolutions, LLC.
Wildlife-vehicle collisions have been a major issue in the area over the past several years.
From 2007 to 2011, striking wildlife accounted for 35 percent of all reported crashes on the highway, the highest rate of any crash type. In the same five-year span, 17 collisions resulted in injuries and three resulted in human fatalities, of the 133 reported to law enforcement.
Eco-resolutions emphasizes that such crashes are likely far more prevalent than the numbers show, and that animal carcasses found on the highway suggest the numbers could be as high as double than what is reported to law enforcement.
How it works
Wildlife crossing is monitored through 24 motion triggering cameras placed at 24 locations along the highway. When triggered the cameras take a series of photos that allow analysts to determine what types of animals are crossing, and their success in doing so.
While mule deer are far and away the most frequent visitors to the crossings, elk, moose, bobcats, coyotes and red fox have also been spotted using the structures.
Aside from the wildlife crossings, other mitigating factors were built to help keep wildlife off the highway including over 10 miles of eight-foot high fencing along the road. Also included in the project were deer guards, wildlife escape ramps and pedestrian walk-through gates.
Deer guards, metal-grates build into the ground to deter wildlife from entering, seem to be the biggest fault in the project so far. Of the 109 deer to visit a deer guard, 38 were able to breach the guard.
The Colorado Department of Transportation developed a new deer guard for the second phase of the project, though data is not yet sufficient enough for analysis.
While the initial results from phase one of the project are promising, long-term monitoring is necessary to understand how different factors like structure type, terrain and species influence the results, says Kintsch.
"It's fantastic, because from the beginning we knew we could prevent accidents on the road, but the important thing is that the highway isn't a barrier for animal movements," said Lyle Sidener, area wildlife manager for Colorado Parks and Wildlife. "The statistics bear that out. We've reduced the vehicle accidents, and also have permeability so the animals are able to cross."