- During the 2017 greater sage-grouse (Centrocercus urophasianus) breeding season, 1,580 aerial and ground lek surveys were conducted at 674 individual lek sites comprising 429 lek complexes. Surveys were conducted at 58.0% of known lek sites in the state. Survey effort during 2017 declined -17.1%, -12.2%, and 14.5% from 2016 levels, in terms of number of surveys conducted, number of leks surveyed, and number of complexes surveyed, respectively. However, even with this decline, survey effort during 2017 was the 2nd highest yet accomplished in the state. Results from these surveys indicate the sage-grouse spring breeding population in Oregon declined by -7.7% between 2016 and 2017, to 20,510 estimated individuals (±1,560 individuals). Magnitude of population trend varied by BLM district analyzed, ranging from a -17.1% decline in the Burns District, to a 1.1% increase in the Vale District.