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NAVHDA members Dean Orosz of Saskatoon, Saskatchewan, and Dean Stainberg of Redding, California, hang fence markers near a sage grouse lek, outside of Wisdom, Montana (Photo Tom Heely)
Madison Griffiths shows the fence marker she snapped into place.
Fence markers work to save sage grouse, according to a new report released by the Bird Conservancy of the Rockies. Funded by an NRCS Conservation Innovation Grant, this is the first study that evaluates the efficacy of using different fence markers to prevent the collisions. Fence-related mortality or injury can occur when sage grouse fly low to the ground over sagebrush range. The study took place on both private and public lands within Sublette County, Wyoming.
The Bird Conservancy of the Rockies’ study was designed to evaluate the collision risk map developed by Brian Stevens, which is described in this SGI Science to Solutions article. The model is also the basis of the Fence Collision Map Layer on SGI’s Interactive Web App.
Sage grouse are most likely to collide with fences when flying toward leks at dawn during spring mating season.
The density of fences in sagebrush country has increased dramatically in over the last 50 years, threatening low-flying sage grouse. Luckily, marking fences with strips of vinyl helps reduce bird collisions. Researchers found 64 confirmed fence collisions by greater sage-grouse during the two-year study, with little difference between areas defined as “high” or “moderate” risk in the pre-existing collision risk map.
The study also found substantial evidence for the ability of markers to reduce collision probabilities (~58% reduction), and little difference between the three marker types investigated. Another interesting finding was the fact that collision probabilities were lower at unmarked fences with wood posts than at marked fences with wood and t-posts.
These conclusions indicate that markers should be placed on fences close to leks, on fencing with t-posts, or in areas with shorter vegetation. In addition, the study shows that the least expensive marker option — vinyl strips without reflective tape — work just as well to prevent collisions, and can be used as the most cost-effective way to save sage grouse.
> Read the full study here
> Read our Science to Solutions on marking fences
> Use the Fence Collision Map Layer on the SGI Web App