(photo: an overpass in Banff)
Problem Statement
Animals move across landscapes to meet
daily, seasonal, and lifetime needs.
Such movements are necessary for survival of individuals
and the persistence of the population and species.
Movements occur across a wide range of scales from daily
movements (meters to kilometers) to seasonal migrations (tens
to hundreds of kilometers) to lifetime movements (thousands of
kilometers in sum). Highways
pose a risk of injury or death to animals whose needs require
crossing when traffic is present.
In turn, animals on highways pose a risk of injury or
death to motorists and property damage to vehicles.
As traffic volumes increase, these risks also increase.
The Yellowstone to Yukon (Y2Y) Initiative seeks to maintain habitat connections so that native wildlife (and plant) species may move across the landscape as necessary to meet their needs to survive and reproduce. Barriers caused by roads and railways pose a significant impediment to wildlife movement at all scales throughout the entire Y2Y area. Attempts to make these barriers permeable to wildlife have only been partially successful due primarily to two factors: 1) the siting of crossing structures, and 2) the design of crossing structures themselves. This study will address both problems by determining the appropriate sites to locate crossing structures, and 2) by involving biologists in the design of crossing structures so that they are large enough and provide sufficient security so that animals can easily use them. Results of the pilot study on Bozeman Pass will be applicable to all other highway barriers within the Y2Y region.
Interstate 90 over Bozeman Pass is just
beginning to experience significant conflicts with wildlife.
As traffic volumes continue to increase the problems will
only get worse. To
anticipate these conflicts and plan for mitigation at this point
will be much more cost-effective if wildlife crossing options
can be included in scheduled construction and maintenance projects
rather than instituted at a later date, perhaps as emergency
measures. Transportation
projects in Florida and North Carolina attest to the expense
of installing special crossing structures. To put Bozeman Pass and I-90 in perspective,
one need only look further south in the Rocky Mountains to I-70
where it passes through the Colorado Rockies.
The traffic volumes and wildlife problems that are currently
occurring there can be expected on I-90 in the near future.
I-70 is virtually impassable to most species of wildlife
except where it passes through tunnels.
To plan for inevitable growth in human populations and
traffic volumes, and to fulfill the mandates of the Transportation
Equity Act for the 21st Century (TEA-21) regarding wildlife needs
and public safety, it is imperative that options for wildlife
conflict mitigation be started as soon as possible on Bozeman
Pass.
Background Summary
Highways and railways are sources of road mortality that threaten wildlife populations through direct mortality, habitat loss, and habitat fragmentation. Animal-vehicle collisions also threaten human safety. Each year, more than 200 motorists are killed and thousands more are injured. The insurance industry estimates that the annual cost to society for these fatalities and injuries is $200 million. Individual motorists usually pay at least $2,000 in vehicle repair every time they hit a large animal (U.S. Dept. of Transportation, 2000). Reducing impacts to wildlife populations requires: "1) fostering greater appreciation of the problems caused by highways and railways, 2) conducting landscape analyses to identify ‘connectivity zones’, and 3) enlisting transportation engineers to help solve technical problems" among others (Jackson, 1999).
The Rocky Mountains run north to south. Landscape features, such as mountain passes, are natural conduits for wildlife movement. Interstate 90 is the only east-west, high-volume four-lane road which impedes animal movement in Montana. Bozeman Pass, located on routes between the Bridger, Gallatin, and Absaroka Mountains contains an interstate highway, frontage road and railroad and is one of the major barriers for animal movement in the region. Forest Service biologists have identified Bozeman Pass as a high-priority, key linkage area in the Northern Rockies due to the cumulative impact of these transportation systems (Ruediger et al, 1999). Traffic volumes on Interstate 90 between Bozeman and Livingston can be expected to increase in the near future as the populations of those cities increase, and as visitation, commercial transportation, and other highway use grows. At current levels, the Interstate, frontage roads, and the Burlington Northern Railroad pose a significant barrier to many wildlife species. Elk, deer, moose, mountain lions, raccoons, black bears and other species are occasionally killed on the highway. In 1998, thirty-nine carcasses were reported only between East Bozeman and Bozeman Pass. (Carl Peil, Personal Communication). The actual number killed is much greater than this since there is currently no systematic road-kill monitoring system. Such animal-vehicle collisions are a traffic hazard, a cause of significant property damage, and a public safety issue, as well as a detriment to wildlife populations. Currently, elk and perhaps other species have been observed using one of the underpasses as a crossing corridor. In anticipation of increasing traffic, serious accidents, and the increasing blockage of wildlife movement, it is wise to begin planning methods to allow wild animals to traverse this transportation corridor safely.
Different species of wildlife have specific habitat needs at various times of the day, season, year, and lifetime in order to survive and reproduce. In order to meet those needs they must move from one type of habitat to another. Daily movements include travel from resting areas to foraging areas and to sources of water. Seasonal and yearly movements include travel from winter range to calving areas to summer range. Lifetime movements include dispersal of young animals from their areas of birth to establish new territories or home ranges. High volumes of traffic along transportation corridors can block, deflect, or delay such movements, and pose a risk of mortality to both wildlife and vehicle occupants. This is a significant problem throughout the Y2Y region.
To provide input into highway construction planning and to allow for the construction of additional underpasses, overpasses, or safety structures, if necessary, it is imperative to provide accurate, systematically collected data on animal movements, and to provide it during the Highway Department systems planning stage for projects that are scheduled to occur 3 to 4 years later. This study will identify the problem-areas for wildlife and human safety at Bozeman Pass and make recommendations about how and where to mitigate wildlife mortality and human safety issues in the connectivity zone.
The inadequacy of current overpasses and underpasses
is obviously due to the fact that they do not sufficiently provide
for the behavioral needs of many wildlife species, especially
their need for security from disturbance.
We feel that they solution lies in providing enough distance
from traffic and enough cover so that sensitive species such
as elk, bears, wolverine etc. can pass across the highway without
being frightened. Current
underpasses and overpasses, such as those constructed in Banff
National Park, are simply not large enough: ideally, the solutions
are 1) to elevate the highway on elevated spans perhaps 1/4 mile
in length and 20 or so feet above a section of natural habitat
including trees and shrubs, or 2) to provide for wildlife passage
over the highway which is essentially in a tunnel of about the
same length and which is covered by natural vegetation to provide
security. We need to work with highway engineers to determine
how closely we can approach this ideal given the constraints
of budgets, engineering features, and local topography.
elevated highway spans
Objectives
At this point, there is already clear
evidence that animal movement in the Bozeman Pass area is causing
highway collisions and that the highway is a significant barrier
to normal animal movements.
This study seeks to further document the current extent
of the problem and to determine how it can best be mitigated.
The study will inform decision-makers where animals cross
between the Bridger and Absaroka Mountains and where wildlife
mortality poses the greatest threat to human safety. This proposal
aims to complete the following objectives:
- Determine the extent of wildlife-human safety conflict at Bozeman Pass, including the location of most wildlife-vehicle collisions.
- Identify the current and potential wildlife use of the linkage zone for various species.
- Determine the best site for wildlife crossing mitigation projects, if warranted.
- Collaborate in design of the type of mitigation structure most appropriate for its location on the landscape and most effective for wildlife passage.
- Evaluate the potential impacts to mitigation structure from adjacent public and/or private lands, and to secure adequate habitat on either side of crossing structures.
Benefits
The Bozeman Pass Wildlife Linkage and Human Safety Study will provide important information to agency officials interested in mitigating wildlife-vehicle collision in a crucial wildlife corridor. Study results will provide scientifically-credible location information for a crossing structure. Results and implementation will provide a model for other highway barriers throughout the Y2Y region. Assuming that the proposed study ends in a mitigation structure in the Bozeman Pass vicinity, wildlife-vehicle collisions will be greatly reduced with a significant cost savings to the general motoring public. Secure wildlife crossing structures will thus increase public safety as well provide an invaluable service to the health of Montana's wildlife species.
Research Plan
Animals tend to move through certain types of habitat depending upon their behavioral and ecological needs. Thus elk tend to travel in open habitats where predators can be sensed and where flight is unhampered. Predators tend to travel in forest or along forest edges where concealment is possible both for stalking prey and for avoiding humans. All species move from one area of secure habitat to another area of secure habitat whenever possible, although the habitat through which they move may be less than optimal. An analysis of habitat conditions bordering a section of highway can identify probable habitat for movement of various species. Coupled with data on animal collision locations, remote camera photos, and animal sign such as tracks, the most important highway crossing sites can be pinpointed. Interpretation of conditions at these sites by biologists that understand the behavioral needs of the various wildlife species involved can determine which mitigations are most likely to allow animals to safely traverse a highway, and which are most likely to be effectively used by animals.
Technical objectives of the study
1) Determine the extent of wildlife-human safety conflict at Bozeman Pass, including the location of most wildlife-vehicle collisions. Data collection has already begun. Currently, volunteers are recording the date, location, and species of road-kills as they commute between Bozeman and Livingston. Interesting or unusual species are further investigated by CERI personnel. All data is entered into a GIS database. In addition the archival and mapping of wildlife collision data will require additional searches of agency records. Known sources include the Montana Department of Fish, Wildlife, and Parks and the Montana Department of Transportation. Additional data may be available from the Montana Highway Patrol and Burlington Northern. These data points are also being entered into a GIS database and mapped to determine active crossing areas.
2) Identify the current and potential wildlife use of the linkage zone for various species. Snow tracking surveys could be implemented in October or November of 2000 as soon as snowfall begins and will continue as long as snow remains along the highway. Track surveys are most effective for 3 to 4 days immediately following a recent snowfall. Other track observations can be made of surfaces that record tracks such as smooth earth, mud, or sand. These surfaces can be prepared at potential crossing sites such as underpasses. Track plates consist of a sticky paper surface on which an animal steps after collecting a layer of soot or other material on its feet. These can be placed at potential crossing sites such as culverts to detect smaller animals. Track plates may be baited to attract animals that are traveling along the margins of the highway and may be attempting to cross, but baiting will not be used where it may cause animals to approach the highway and thus influence their natural movement routes. All data points would then be entered into a GIS database. Remote cameras utilize motion sensors to photograph animals crossing in front of the camera at key sites such as underpasses, bridges, or areas where habitat cover extends close to the highway along natural movement routes such as ridges or riparian areas. Cameras are checked regularly and film is replaced. The use of digital cameras appears to be more cost-effective since there is no film or development cost. In addition, digital cameras provide real-time data, which is often important in order to make additional observations. However, digital cameras require large battery capacity; their use will be evaluated as the project proceeds.
3) Determine the best site for wildlife crossing mitigation projects. Spatially explicit GIS habitat suitability models can be developed from data layers currently available. Analysis methods such as mapping zones of disturbance around human developments like houses and secondary roads, using least-cost-path analysis to determine travel routes containing the best security, mapping of attractant or repellant features that may direct animal movement, can be employed to determine focal areas for more intense field surveys. The project will present the available evidence for wildlife movement, habitat use, frequency and location of collisions and danger to public safety and analyze options for mitigating conflicts with wildlife. The report will provide data upon which MDT can base decisions for implementing TEA-21 wildlife and public safety mandates.
In addition, if sufficient funding is obtained, detailed movement data could be obtained by working cooperatively with the Montana Department of Fish, Wildlife, and Parks to use GPS radio-collars on a few animals. GPS collars would provide hour-by-hour movement data on elk, deer, and perhaps black bear. Deployment and monitoring of GPS collars would not likely begin before mid-summer depending upon the time constraints of agency personnel. However, the deployment of GPS radio-collars in late summer or fall would provide important, detailed, data on movement of elk herds, deer herds, and perhaps dispersing carnivores or those that were preying upon resident elk and deer. GPS data may be extremely important to verify crossing points and attempted crossing points and ultimately may provide the most convincing evidence to the Department of Transportation in terms of justifying the expense of a mitigating structure at a certain location.
4) Collaborate in design of the type of mitigation structure most appropriate for its location on the landscape. Researchers will evaluate wildlife crossing and collision information to determine potential sites for wildlife crossing structures. Landscape and highway features, such as high cliffs, broad valleys, streams, fencing, and existing culverts, will help determine the options for mitigation. These options will be discussed with MDT personnel during site visits and at various stages in the project. An expert panel will be convened to include respected scientific authorities on the species in question and highway design engineers to determine the best feasible design for crossing structures at each crossing site.
5) Evaluate the potential impacts to mitigation structure from adjacent public and/or private lands. In collaboration with the Gallatin Valley Land Trust, American Wildlands, the Trust For Public Lands Yellowstone to Yukon members, and other governmental and non-governmental organizations in Bozeman and Livingston, researchers will investigate lands adjacent to I-90. A critical part of mitigation will be the status of land ownership and wildlife habitat adjacent to the highway right-of-way at potential crossing sites. The study will evaluate current habitat conditions, conservation easements, and land status on adjacent public and/or private lands as well as opportunities for cooperation with landowners or managers.
Products
Progress reports and a final report including GIS maps of crossing sites will be prepared and distributed to all involved parties including the Montana Department of Transportation which will receive continual communications and reports that are consistent with their construction and maintenance planning schedules. Timely materials will be distributed to the entire Y2Y network so that implementation of similar solutions can be integrated as soon as possible into the planning stages of other highway projects in both the U.S. and Canada. In addition, GIS maps, photographs, and power point presentations will be prepared to facilitate the communication of the study results.
Implementation
GIS maps will summarize location data for wildlife-vehicle collision, wildlife movement corridors, wildlife habitat, and potential sites for wildlife crossing structures. These maps will be useful to engineers and administrators for understanding and designing mitigation solutions. Public informational sessions in Bozeman and Livingston will provide timely information to the general public and all involved parties in order to maintain public support and understanding of the project. We will consult with the Environmental Services, Engineering, and Biological staff at MDT throughout the project implementation. These MDT staff will apply the research results to designing mitigation solutions in the Bozeman Pass vicinity.
Current results will be disseminated throughout the Y2Y network as soon as they become available. Whenever and wherever possible public informational sessions will be provided in other parts of Y2Y so that Y2Y members facing similar problems can be kept abreast of developments. This is extremely important so that data and approaches can be provided to other highway departments at an early stage in planning. Highway engineers need to plan at least 3 to 4 years in advance in order to incorporate design changes such as crossing structures into highway plans.
The convening of an expert panel of biologists and engineers will be extremely important in determining and validating the types of structures that will be most effective in allowing wildlife crossing of highways. An initial panel should be convened in 2001 to approach consensus on the basic design of structures that can provide security for wildlife as well as meet engineering requirements. A more focused panel will be convened in 2002 to provide site specific specifications for the most feasible crossing structures for each of the identified crossing sites. Results of the initial panel will be extremely valuable for other areas of Y2Y in order to begin thinking and planning for mitigation. Site specific investigations will then need to be undertaken in each area following the model that is developed by this pilot project.