Evaluating Fall Monarch Roadkill Hotspot Incidence and Potential Roadkill Mitigation

The monarch butterfly (Danaus plexippus) was petitioned for protection under the federal Endangered Species Act in 2014. The listing decision is pending. This action was triggered by the observation that overwintering populations of the eastern migrating monarchs in central Mexico had declined by 82 percent in the 23 years from 1995 to 2018. This rate of decline is compelling evidence that monarch populations have been reduced to the point where persistence of the migratory phenomenon is endangered. Recent research identified that roadkill mortality occurring on Texas roadways is a major mortality factor associated with both the coastal and central flyways used in migration through Texas to the overwintering sites in Mexico. Migrating monarch become more concentrated as they travel south, amplifying the effects of roadkill on populations. Mortality occurs in hotspots associated with landscape and infrastructure features of Texas roadways. This project's aim is to identify hotspot locations, zones, and regions for monarch roadkill mortality and investigate mitigation actions that could be implemented to reduce monarch/vehicle collisions. To accomplish this goal the Performing Agencies will conduct surveys to identify hotspot locations, correlate hotspot locations with environmental and road infrastructure features, develop maps of roadkill mortality over major Texas highways, and evaluate potential mitigation options.


  • English


  • Status: Completed
  • Funding: $348295
  • Contract Numbers:


  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483
  • Managing Organizations:

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483
  • Project Managers:

    Steele, Joanne

  • Performing Organizations:

    Texas A&M Transportation Institute (TTI)

    400 Harvey Mitchell Parkway South
    Suite 300
    College Station, TX  United States  77845-4375
  • Principal Investigators:

    Coulson, Robert

  • Start Date: 20190731
  • Expected Completion Date: 20210831
  • Actual Completion Date: 20210831

Subject/Index Terms

Filing Info

  • Accession Number: 01715962
  • Record Type: Research project
  • Source Agency: Texas Department of Transportation
  • Contract Numbers: 0-7022
  • Files: RIP, STATEDOT
  • Created Date: Sep 10 2019 5:45PM