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BRIEF RESEARCH REPORT article

Front. Ecol. Evol.
Sec. Biogeography and Macroecology
Volume 12 - 2024 | doi: 10.3389/fevo.2024.1487911

USA-Mexico border wall impedes wildlife movement

Provisionally accepted
Eamon Harrity Eamon Harrity 1*Myles Traphagen Myles Traphagen 2Meagan Bethel Meagan Bethel 1Aaron Facka Aaron Facka 2Michael Dax Michael Dax 2Emily Burns Emily Burns 1
  • 1 Sky Island Alliance (United States), Tucson, United States
  • 2 Wildlands Network, Salt Lake City, Utah, United States

The final, formatted version of the article will be published soon.

    Geopolitical boundaries can present challenges to wildlife conservation because of varying environmental regulations, and increasingly, the existence of border barriers. As of 2024, approximately 1,023 km of border walls (i.e., steel bollard walls 5.5-9.1 m tall with interstitial spaces ≤10 cm) and 169 km of vehicle barriers (i.e., variable steel structures designed to stop vehicles but not pedestrians) exist along the USA-Mexico border. Some small wildlife passages (µ = 21.5 x 27.8 cm) were installed in border walls but few other accommodations for wildlife connectivity exist. As such, ecological consequences of border barriers may be severe and documenting the ability of wildlife to traverse these barriers will be essential to conservation efforts. We placed 36 wildlife cameras across 163.5 km of the USA-Mexico border in Arizona, USA and Sonora, MX to evaluate crossing rates through border barriers for 20 terrestrial species. We observed 9,240 wildlife events, including 1,920 successful crossing events. All focal species crossed through vehicle barriers, whereas white-tailed deer, mule deer, American black bear, American badger, wild turkey, and mountain lion appeared unable to cross through interstitial spaces in border walls. Small wildlife passages improved crossing rates for several species, including American badger, collared peccary, coyote, and mountain lion. Yet, small wildlife passages were scarce with only 13 along >130 km of continuous border wall and failed to allow American black bear, deer, and wild turkey to cross. Additional research on the impacts of border barriers and potential mitigation strategies will be critical for effective transboundary conservation.

    Keywords: Border wall, Border barrier, connectivity, Wildlife crossing, Movement, transboundary conservation

    Received: 29 Aug 2024; Accepted: 30 Oct 2024.

    Copyright: © 2024 Harrity, Traphagen, Bethel, Facka, Dax and Burns. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Eamon Harrity, Sky Island Alliance (United States), Tucson, United States

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.