Evaluation of road expansion and connectivity mitigation for wildlife in southern California

Southwestern Naturalist
By: , and 



We designed a remote-camera survey to study how the expansion of California State Route 71 (CA-71) and implementation of connectivity mitigation affected the use of underpasses by large mammals in southern California. Based on detections by cameras, the use of underpasses by bobcats (Lynx rufus) was higher within the area of expansion and mitigation after construction than before, but there was no difference in use of underpasses in the impact zone compared to the control zone before or after construction. Use of underpasses by coyotes (Canis latrans) was higher in the control zone than in the impact zone, but there was no difference in use before and after construction. Small numbers of detections of mule deer (Odocoileus hemionus) at only a few underpasses precluded comparison between control and impact zones. However, a comparison of use before and after construction revealed that use of underpasses by mule deer was slightly higher post-construction. We cannot fully attribute increased detections post-construction to mitigative efforts, because other factors, such as availability of habitat, urbanization, or demography, also may have influenced use of underpasses along CA-71. Nonetheless, even with the expansion of the freeway and subsequent increase in volume of traffic, mitigative structures along CA-71 did allow for continued movement and, hence, connectivity across the roadway for large mammals.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Evaluation of road expansion and connectivity mitigation for wildlife in southern California
Series title Southwestern Naturalist
DOI 10.1894/F04-TAL-51.1
Volume 59
Issue 2
Year Published 2014
Language English
Publisher Southwestern Association of Naturalists
Contributing office(s) Western Ecological Research Center
Description 7 p.
First page 181
Last page 187
Country United States
State California
Online Only (Y/N) N
Additional Online Files (Y/N) N
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