Analysis Begins On Effectiveness Of Wildlife Bridge On Parleys Summit
The Parley's Summit wildlife bridge has been in place since the fall of 2019. An analysis is underway to determine its effectiveness compared to other wildlife crossings in Utah.
Utah State University Associate Professor Dr. Nicki Frey (FRY) is a Ph.D. wildlife biologist who will handle the Utah Department of Transportation analysis. She said there is one other bridge structure on I-70 and many underpasses. Wildlife underpasses are part of all new highway construction. UDOT has used them for more than 20 years. UDOT built the bridge but has contracted with Utah State to do the analysis.
She said they'll measure usage with cameras and video installed on the Parleys Summit bridge. They'll consider the various species that are using the structure.
"Do we see a host of different species, whether they be ungulates such as deer, elk, and moose, carnivores like mountain lions or Bobcat or even small mammals. So the more we have different species using it, the more we can say that it is friendly towards all wildlife species, and then we'll also look at it as far as time of day and time of year. So are migratory animals using it during their migration route?"
Frey said the overpass should facilitate migration. Highways can be a barrier for large animals that have an instinct to move along their natural migration routes, and they'll take their chances of crossing the highway. She said collisions with vehicles are costly both to animals and humans.
They'll use UDOT's underpass data for comparison with other crossings around the state. The analysis begins this fall. The immediate success of the wildlife bridge has surprised the experts who study wild animal behavior.
"In the 15 months that we've been collecting the data, we have over 2700 detections of wildlife, just an exponentially larger level of success than we expected to find. Of those detections, roughly 700 of them were actual animals coming across."
During the 15-month observation period, they detected 320 deer, 72 coyote's,16 moose 30 porcupines, nine black bears, ten bobcats, 25 racoons, 49 rock squirrels, and many unknown small animals using the bridge that crosses I-80. Frey said the high use suggests the overpass has integrated into the surroundings quicker than they expected.
"Either we've got smart deer, and the overpass is really integrating seamlessly into the environment, which does credit UDOT really well. But also, it may indicate that the deer were very limited in their ability to migrate across it. And so, they had kind of a buildup of pressure so that as soon as there was a safe passage, they started to use it right away."
Frey said she would compile the video footage this fall and make it available by late October for interested people. They have a live video feed running 24-7 and collect data on ten cameras on the overpass. The analysis could take about a year to complete.