The Greater sage-grouse (Centrocercus urophasianus) has been the subject of both research and monitoring on the INL Site since the mid-1970s. In 2006, S. M. Stoller, through the Environmental Surveillance, Education and Research Program, partnered with the Wildlife Conservation Society (WCS) to initiate a project that will culminate in the completion of a Conservation Management Plan (CMP) for a variety of animal species in the development zone on the INL Site. Because greater sage-grouse is considered a candidate species, one of the principle components of the CMP will be a Candidate Conservation Agreement between DOE-ID and the USFWS concerning conservation actions that DOE-ID will take to minimize threats to sage-grouse.

Determining Greater Sage-grouse Abundance and Seasonal Landscape Use Patterns on the Idaho National Laboratory Site

Objective: Our objective was to conduct a multi-year survey of historic leks that were previously identifi ed by the Idaho Department of Fish and Game and National Environmental Research Park researchers over the past 40 years to determine if those sites were still used by Greater Sage- Grouse.

Summary: Currently, 26 sage-grouse leks are known to be active on the INL Site. In addition, 61 leks are documented that were historically active but for which the current status is unknown. Surveys of historically documented leks were conducted on and adjacent to the INL Site in 2009. Only 57 of the historical leks were surveyed because the remainder either had been displaced by human activity, or a known active lek was close by.

The 57 historical lek sites were visited one or more times (101 total visits). Sage-grouse were detected visually or audibly on or near 17 historic and 3 previously undocumented leks. At least two males were detected on all but fi ve of the 20 sites during the survey period. Of the 39 leks where sage-grouse were not detected, 13 (33 percent) were surveyed twice.

Each lek was classified according to the Idaho Department of Fish and Game criteria for our results in 2010. At five leks, only one male was observed at each site. As such, there were insuffi cient data to assign those leks an active status. There were seven leks that were designated as active in 2009 that had < 2 males during our surveys in 2010. Those seven leks remain designated as active. The other 16 leks where sage-grouse were detected (including three that were previously undocumented) were designated as active. Of the 16 leks, there were five historic leks that were designated unknown in 2009 that are now determined to be active. In addition, six leks were designated as inactive and 33 as unknown.

Each spring in the future, all historical leks will be surveyed again. Ultimately, once all active sites are identifi ed, the broader objective will be to quantify the number of males visiting leks from year to year (i.e., lek census) to understand population trends on the INL Site.

STOLLER-ESER-141 Annual Report of Surveys for Historic Sage-Grouse Leks on the Idaho National Laboratory - Jericho C. Whiting and Bryan Bybee - March 2011