Amanda Hardy

An Assessment of Road Impacts on Wildlife Populations in U.S. National Parks

Current United States National Park Service (NPS) management is challenged to balance visitor use with the environmental and social consequences of automobile use. Wildlife populations in national parks are increasingly vulnerable to road impacts. Other than isolated reports on the incidence of road-related mortality, there is little knowledge of how roads might affect wildlife populations throughout the national park system. Researchers at the Western Transportation Institute synthesized information obtained from a system-wide survey of resource managers to assess the magnitude of their concerns on the impacts of roads on park wildlife. The results characterize current conditions and help identify wildlife-transportation conflicts. A total of 196 national park management units (NPS units) were contacted and 106 responded to our questionnaire. Park resource managers responded that over half of the NPS units’ existing transportation systems were at or above capacity, with traffic volumes currently high or very high in one quarter of them and traffic expected to increase in the majority of units. Data is not generally collected systematically on road-related mortality to wildlife, yet nearly half of the respondents believed road-caused mortality significantly affected wildlife populations. Over one-half believed habitat fragmentation was affecting wildlife populations. Despite these expressed concerns, only 36% of the NPS units used some form of mitigation method to reduce road impacts on wildlife. Nearly half of the respondents expect that these impacts would only worsen in the next five years. Our results underscore the importance for a more systematic approach to address wildlife-roadway conflicts for a situation that is expected to increase in the next five to ten years.

Behavioral responses of bison and elk in Yellowstone to snowmobiles and snow coaches.

Managers of public lands are charged with protecting some of our most important natural resources and ecosystems, while providing for their use and enjoyment by visitors. Almost one million visitors entered Yellowstone National Park by motorized means on snowmobiles (87%) or snow coaches (13%) during 1992-2003. Most vehicles toured the central portion of the park where bison (Bison bison) and elk (Cervus elaphus) concentrate in geothermal areas. We sampled >6500 interactions between groups of these species and groups of snowmobiles and snow coaches (collectively, OSV, over-snow vehicles) during five winters (1999-2000, 2002-2004). Multinomial logits models were used to identify conditions leading to behavioral responses. Elk responded three times as often (52%) as bison (19%) during interactions with groups of snowmobiles and snow coaches due to increased vigilance responses (elk, 44%; bison, 10%). However, the frequency of higher-intensity movement responses by bison and elk were similar (6-7% travel, 1-2% flight, <1% defense) and relatively low compared to other studies of ungulates and snowmobile disturbance. The likelihood of active responses by bison and elk increased significantly if animals were on or near roads, groups were smaller, or humans approached. The likelihood of an active response by bison decreased within winters having the largest visitation, suggesting some habituation to snowmobiles and snow coaches. There was no evidence that snowmobile use during the past 35 years affected the population dynamics or demography of bison or elk. Thus, we suggest that regulations restricting levels and travel routes of over-snow vehicles (OSVs) were effective at reducing disturbances to bison and elk below a level that would cause measurable fitness effects. We recommend park managers consider maintaining OSV traffic levels at or below those observed during our study. Regardless, differing interpretations of the behavioral and physiological response data will continue to exist because of the diverse values and beliefs of the many constituencies of Yellowstone.

Effectiveness of Animal Advisory Messages on Dynamic Message Signs as a Speed Reduction Tool: Case Study in Rural Montana

Animal-vehicle collisions (AVCs) are a growing concern as the number of vehicle miles traveled and human encroachment into wildlife habitat increase throughout the United States. Measures to prevent AVCs, such as fencing and wildlife passages, can impose significant investments for transportation agencies. An alternative and potentially less expensive approach is the use of signs to modify driver behavior to reduce these collisions. This study investigated the effectiveness of seasonal animal movement advisories as a speed reduction tool on Interstate highways. Two permanent and one portable dynamic message signs (DMSs) were used to post messages advising motorists to watch for wildlife moving across Interstate 90 in the Bozeman Pass region of southwestern Montana. One control and three treatment messages were displayed on the DMSs, and driver reactions to these messages were recorded through speed observations. The control message comprised a blank message; and the treatment messages included a general t...

Developing the Integrated Transportation and Ecological Enhancements for Montana Process: Applying the "Eco-Logical" Approach

Construction and maintenance of transportation systems can result in direct, indirect, and cumulative effects on ecosystems. Mitigation of unavoidable adverse impact typically occurs on a project-by-project basis and commonly attempts to restore the same affected resource near the site at which the impact occurs. This piecemeal approach may fulfill regulatory requirements, but greater mitigation value may be achieved with a similar investment by evaluating and prioritizing off-site mitigation opportunities in the context of the entire ecosystem. In addition, project-by-project environmental permitting practices involve repetitious procedures that sometimes unpredictably delay project delivery. A recent federal guide encourages agencies to plan infrastructure projects and related mitigation with goals of conserving and connecting important habitat collaboratively and strategically, while increasing predictability and transparency of planning and regulatory permitting processes. This guide, Eco-Logical: An Ecosystem Approach to Developing Infrastructure Projects, was used by an interagency group in Montana to create the Integrated Transportation and Ecosystem Enhancements for Montana (ITEEM) process. As the first effort to pilot Eco-Logicals guidance, cooperating agencies gained insights that may help others follow Eco-Logicals framework. This paper summarizes Montanas efforts to adapt Eco-Logical to create the ITEEM process and offers insights for other interagency efforts to increase the efficiency of transportation project delivery while mitigating adverse impacts where the conservation efforts are most needed.