Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): K. A. Zeller; D. W. Wattles; L. Conlee; S. Destefano
    Date: 2020
    Source: Animal Conservation. doi: 10.1111/acv.12621.
    Publication Series: Scientific Journal (JRNL)
    Station: Rocky Mountain Research Station
    PDF: Download Publication  (986.0 KB)


    Roads can result in negative effects on wildlife including habitat loss, behavioral avoidance, reduced survival, reproduction and gene flow. These road effects are especially pronounced for large mammals given their large home-range requirements and low reproductive rates. To counteract these negative effects, road mitigation measures, such as underpasses and overpasses, are promoted; however, future landscape changes are rarely considered when selecting mitigation locations. We used GPS telemetry data on female American black bears Ursus americanus to examine their response to roads in Massachusetts, US. We compared bear road crossing frequency with a null crossing model derived from a correlated random walk, estimated road crossing movement speeds, and fit a road-crossing resource selection function. We found that, though black bears crossed roads less than expected based on the null model, 10% of their observed steps, on average, crossed roads. We also found bears crossed roads at higher movement speeds than during other home-range behaviors, and that bears preferred to cross smaller, less trafficked roads in areas with lower speed limits, less human development and more forest. We used the resource selection model to identify road segments for potential mitigation efforts and then used future human development projections to forecast future changes in these segments. We found a decrease of 15% in the length of suitable mitigation segments from 2019 to 2050. Given the sizeable investment in wildlife crossing structures and their longevity on the landscape, we recommend incorporating future projections into crossing site selection to ensure the long-term viability of road mitigation efforts.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Zeller, K. A.; Wattles, D. W.; Conlee, L.; Destefano, S. 2020. Response of female black bears to a high-density road network and identification of long-term road mitigation sites. Animal Conservation. doi: 10.1111/acv.12621.


    Google Scholar


    road ecology, black bear, movement ecology, multi-scale selection, future projections, human development

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page