Periodic Status Review for the Greater Sage-grouse in Washington (Apr 2021)

The Greater Sage-grouse (Centrocercus urophasianus) historically was found throughout the shrubsteppe areas of eastern Washington. The species is now limited in distribution in the state to Douglas County, the Joint Base Lewis-McChord Yakima Training Center (JBLM-YTC), and Lincoln County where a reintroduction project re-established a small population. The state-wide population estimate, based on lek counts, was 775 in spring 2020, an increase from 688 birds in 2019, as a result of an increase in Douglas County from 597 to 697, while Lincoln County decline from 13 to 10, and the JBLM-YTC declined from 78 to 68. Subsequent to those counts, the habitat of all three populations were affected by wildfires. Preliminary assessments suggest that the Douglas County population will be reduced by ~50% due to loss of sagebrush on half the occupied habitat, and mortalities primarily from high predation due to lack of cover. The struggling Lincoln County population will probably be extirpated.

The sage-grouse was state-listed as threatened in 1998, and a state recovery plan was completed in 2004. From 2001–2015, the Columbia Basin sage-grouse population was a candidate for listing as a threatened Distinct Population Segment (DPS) under the U.S. Endangered Species Act. In September 2015, the U.S. Fish and Wildlife Service issued a decision that the population in Washington did not meet the criteria for a DPS and listing of the Greater Sage-grouse across its entire range was not warranted. However, since that decision, genomic analyses highlighted the unique nature of the Washington population.

The potential for wildfires to eliminate sagebrush (Artemisia spp.) on extensive areas has been the greatest ongoing threat to sage-grouse in Washington, as we have seen in 2020. However, with the continued decline, all of Washington’s populations are now likely suffering from problems with genetic health and fitness related to small population size. Uncertainty about the long-term maintenance of habitat that depends on Farm Bill programs (CRP/SAFE) is also a concern. Other major management issues include habitat that is fragmented by roads, agriculture, and development and degraded by past wildfires, historical excessive livestock grazing, fencing, electrical transmission lines, and exotic vegetation. Sage-grouse may suffer mortality rates above historical levels as a result of collisions with fences, powerlines, and vehicles, and higher populations of some generalist predators, especially ravens and coyotes.

The Washington Department of Fish and Wildlife (WDFW) and several partner organizations are working on habitat and other aspects of sage-grouse recovery. Without these efforts, the sage-grouse would likely decline to extinction in Washington. In Spring 2020, sage-grouse had not yet declined to populations levels indicated in the 2004 state recovery plan for up-listing (<650 birds); however, that was before the devastating fires of September, and the threshold assumed that the Douglas County and JBLMYTC populations were connected, which now appears unjustified. Due in part to their polygynous mating system, the effective size of the three populations are ~108 birds for Douglas County and 10 birds for JBLM-YTC. Extinction of the Lincoln County population is all but certain, and of the JBLM-YTC within a decade or so is likely unless they can be increased substantially. The hope of any reintroductions in the future is tempered by the recent failure of the reintroduction project by the Yakama Nation, the probable failure of the Lincoln County population, and the continued loss of habitat in suitable condition by wildland fire.

Concurrent with this troubling decline, genomic analysis has indicated that Washington’s population is more distinct than the Bi-state population that was proposed for listing as a threatened ‘Distinct Population Segment’ under the Endangered Species Act (USFWS 2019). For these reasons, it is recommended the sage-grouse be up-listed to endangered in Washington.