The magnitude of the US 93 North reconstruction project offers an unprecedented opportunity to evaluate to what extent these mitigation measures help improve safety through a reduction in wildlife-vehicle collisions and to what extent they maintain habitat connectivity for wildlife.
In addition, the landscape along US 93 North is heavily influenced by human use, in contrast to the more natural habitats along most of the other road sections that have large-scale wildlife mitigation in North America. Since roads with most wildlife-vehicle collisions are in rural areas influenced by human use, the results from the US 93 North project are expected to be of great interest to agencies throughout North America.
In 2002, prior to US 93 North’s reconstruction, data were collected and a final report on the preconstruction monitoring findings was published in 2007. While the preconstruction monitoring and research efforts are valuable on their own, their main purpose is to provide a reference for a before-after comparison with the post-construction data.
In 2010 MDT contracted with WTI-MSU to conduct the post-construction research evaluating the effectiveness of the mitigation measures. For this project, the CSKT act as a subcontractor to WTI-MSU. This post-construction evaluation will be completed in 2015.
The goals of the research are to investigate the “effectiveness” of the wildlife crossing structures and wildlife fencing and to identify best management practices and further research that may benefit future wildlife-vehicle collision reduction and wildlife crossing mitigation projects. Consistent with the direction provided by MDT, the project is centered on three main subjects:
- Improvement in human safety through a reduction in wildlife-vehicle collisions;
- Maintaining habitat connectivity for wildlife through the use of the wildlife crossing structures; and
- A cost-benefit analyses for the mitigation measures.
For a detailed description of data collection methods and the research plan, please see Huijser et al. 2009’s Proposal.
Generally, data collection and monitoring methods include:
- Collection of the number of animal-vehicle collisions through Montana Highway Patrol accident reports, MDT carcass removal reports, and Montana Fish, Wildlife, and Parks bear road mortality data
- Digital motion-sensitive wildlife cameras (see picture) at the majority of crossing structures, ends of fences, and jump-outs
- Sand tracking beds at jump-outs and selected crossing structures
- Deer pellet group surveys to measure potential changes in the deer population size
During 2010, 2011, and 2012, over 53,600 wildlife movements have been documented with use by over 30 species. The majority of movements is by white-tailed deer, mule deer, and domestic dogs and cats (Figure 1 and Table 1). Thousands of ‘other’ species have used the structures as well (Table 2). The estimate is reported as a minimum because not all 41 structures on US93N are monitored using wildlife cameras.
To see great pictures of wildlife using the structures, head to the Photo Gallery page!
Figure 1. Wildlife use of 27 wildlife crossing structures monitored in 2010, 2011, and 2012 (total 53,604)
Table 1. Wildlife use of 27 wildlife crossing structures monitored in 2010, 2011, and 2012 (total 53,604)
|Other (unknown species)||1,660||2,358||2,214|
Table 2. Number and percentage of wildlife use in the “other” category in Figure 1 and Table 1
|Western striped skunk||86||124||142|
|Rabbits and hares||26||55||38|
|Bear (unk species)||10||3||2|
|Canine (unk dog vs coyote)||73||0||0|
|Deer (unk species)||561||63||186|
Other Research on US93N
Research on the wildlife crossing structures has been completed by several graduate students .