Exploring Mitigation Options to Reduce Vehicle-Caused Mortality of a Threatened Butterfly

Roads that bisect habitat can lead to a decline in population size due to animal-vehicle collisions or interruption of key life history events. Along the Oregon central coast, Highway 101 divides breeding from nectaring habitat of the Oregon silverspot butterfly (OSB; Speyeria zerene hippolyta), a federally listed species. We evaluated which of several proposed management techniques for reducing vehicle-caused deaths of OSBs should be pursued further. We could not directly evaluate each, so we gathered information on behavioral ecology relevant to each management option. OSBs did not prefer the road or road-cut for basking or flying, suggesting mitigations to increase wind in the road would likely not be effective. Rather, OSBs crossed the road in areas that had more flowering plants along the verge; hence, vegetation management would likely be an effective mitigative measure. Because most crossings were concentrated in specific areas, barrier installation to increase flight height is also recommended. Reduction of traffic speed when road temperature is just over 19.0°C, a threshold temperature correlated with flight, also may reduce vehicle-related OSB mortality. We found gathering targeted ecological information was an effective approach for prioritizing management options.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Zielin, Sara Beth
  • de Rivera, Catherine E
  • Smith, Winston P
  • Jacobson, Sandra L
• Conference:
  • Transportation Research Board 90th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2011-1-23 to 2011-1-27
• Date: 2011

Language

• English

Media Info

• Media Type: DVD
• Features: Figures; References; Tables;
• Pagination: 16p
• Monograph Title: TRB 90th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Animal migrations; Animal vehicle crashes; Endangered species; Environmental impacts; Habitat (Ecology); Roadside fauna; Vegetation; Wildlife
• Uncontrolled Terms: Mortality; Wildlife mitigation
• Subject Areas: Environment; Highways; I15: Environment;

Filing Info

• Accession Number: 01337532
• Record Type: Publication
• Report/Paper Numbers: 11-2834
• Files: TRIS, TRB
• Created Date: Apr 21 2011 1:09PM