Surfbirds News

Greater Sage-grouse © Bill Schmoker, from the surfbirds galleries.

The study was conducted along 4.7 miles of fence on Wyoming’s Sweetwater-Sublette County Line, following several anecdotal reports of dead sage-grouse on fences. It involved both monitoring for dead birds and testing potential solutions. The study fence yielded 146 Greater Sage-Grouse deaths over a period of seven months, a worrying number given the precarious status of the species, whose range and population have declined by as much as 90% in recent decades. The researchers determined that some fences are more dangerous than others. Those constructed with steel t-posts near leks (breeding grounds) or bordering riparian areas or that bisect winter concentrations are the most deadly. Fences constructed in areas with greater topographic relief result in fewer deaths, presumably because the birds must fly higher to clear the ground, and are therefore less likely to hit the fences.

Encouragingly, the researchers found that mitigation in the form of fence markers was an effective way of preventing sage-grouse deaths. Currently available commercial markers reduced deaths by 60-70%, but the study authors were optimistic that this figure could be further improved with some design modifications. The authors recommended that no new fence be built within ¼ mile of a sage-grouse lek, and that existing fences be thoroughly surveyed to see if they are a threat (which means walking or slowly driving the fenceline regularly so that carcasses are spotted before scavengers have had a chance to take them).

The recent study may have some bearing on the forthcoming FWS decision on whether to give the Greater Sage-Grouse under the Endangered Species Act. Any determination by the Service to list the species would have a significant impact on energy and other land management issues such as grazing in areas where the sage-grouse occurs.

In 2005, the Service issued a finding that Endangered Species Act listing was not warranted for the sage-grouse. However, that decision was overturned in a district court appeal due to suspicion that it may have been unduly influenced by former Deputy Assistant Interior Secretary Julie MacDonald, who was forced to resign over a controversy that involved her personal involvement in listing decisions of other species. Then FWS Director Steve Williams defended the original decision on the basis of stabilized or increasing sage-grouse populations. The new decision on listing the species must be made by February 2010 as ordered by the court.