Abstract
Pronghorn (Antilocapra americana) is an endemic North American ungulate susceptible to negative effects of fences, especially given the vast amount of barbed-wire fencing currently on the landscape. Despite multiple nongovernmental organizations, and state and provincial wildlife agencies publishing guidelines for creating wildlife-friendly fencing, there are no published studies that evaluate and compare evidence of the effectiveness of endorsed practices. We analyzed pronghorn crossing success in Alberta, Canada, and Montana, USA, between 2012 and 2016 in response to fence-modification treatments to understand 1) differences between bottom wire height at selected versus available fence sites, 2) the change in crossing rates before and after fence modification treatments, 3) the effect of a suite of fence, environmental, and demographic characteristics on group crossing success, and 4) the time lag until pronghorn became habituated to different fence modifications after initiation of treatments. Use of either smooth wire or clips with a bottom wire height of approximately 46 cm were most effective at allowing passage by pronghorn, while the commonly proposed goat-bar was ineffective and created a negative behavioral response by pronghorn. Though smooth wire and clips were effective at allowing passage, we observed a time lag as pronghorn switched use from their strong fidelity at known-crossing sites to using modified sites. Pronghorn-group crossing success was greatest during summer, for all-male groups, and increased with larger group sizes. We advocate not using goat-bars as modifications to fences, and instead, recommend using smooth wire and clips at a minimum bottom-wire height of 46 cm to allow movement by pronghorn. Our study provides guidance for wildlife-friendly fencing techniques to wildlife managers and private landholders as a means to improve permeability for pronghorn and additionally, can be used as a model to evaluate fence modifications for pronghorn and other target species that may be sensitive to fence interactions.
| Original language | English |
|---|---|
| Pages (from-to) | 225-236 |
| Number of pages | 12 |
| Journal | Wildlife Society Bulletin |
| Volume | 42 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jun 2018 |
Funding
We thank the following folks for their tireless efforts in the field and photo processing during data collection in Alberta: R. Anderson, J. Baker, A. Barreto, S. Borsato, T. Council, A. Cutway, B. Downey, M. Jensen, T. Johns, D. Kilfoyle, N. Mackintosh, L. Seward, and M. Sharren; and in Montana: E. Burkholder, J. Hanlon, C. Messerly, J. Messerly, B. Nickerson, A. Redfern, and K. Terry. A thank you to D. Kilfoyle and B. Taylor at Canadian Forces Base Suffield for coordinating our access to the sites and putting up with our comings and goings. We thank J. Hasbani for the development of our custom database and continued technical support. Assistance with statistical analysis was provided by C. Schwarz, for which we are truly thankful. Financial and in-kind support for this project was provided by Alberta Conservation Association, Alberta Fish and Game Association, Bushnell Canada, Cabela’s Canada, Miistakis Institute of the Rockies, National Fish and Wildlife Foundation, Safari Club International—Northern Alberta and Billings Chapters, and The Nature Conservancy. Lastly, we thank Associate Editor C. Anderson and 2 anonymous reviewers for their comments and insights on an earlier draft, which greatly improved our paper.
| Funders |
|---|
| Alberta Conservation Association |
Keywords
- Antilocapra americana
- Northern Sagebrush Steppe
- clip
- fence modification
- goat-bar
- pronghorn
- smooth wire