Can Reliable Sage-Grouse Lek Counts Be Obtained Using Aerial Infrared Technology?

Abstract

More effective methods for counting greater sage-grouse (Centrocercus urophasianus) are needed to better assess population trends through enumeration or location of new leks. We describe an aerial infrared technique for conducting sage-grouse lek counts and compare this method with conventional ground-based lek count methods. During the breeding period in 2010 and 2011, we surveyed leks from fixed-winged aircraft using cryogenically cooled mid-wave infrared cameras and surveyed the same leks on the same day from the ground following a standard lek count protocol. We did not detect significant differences in lek counts between surveying techniques. These findings suggest that using a cryogenically cooled mid-wave infrared camera from an aerial platform to conduct lek surveys is an effective alternative technique to conventional ground-based methods, but further research is needed. We discuss multiple advantages to aerial infrared surveys, including counting in remote areas, representing greater spatial variation, and increasing the number of counted leks per season. Aerial infrared lek counts may be a valuable wildlife management tool that releases time and resources for other conservation efforts. Opportunities exist for wildlife professionals to refine and apply aerial infrared techniques to wildlife monitoring programs because of the increasing reliability and affordability of this technology.

Computer-automated bird detection and counts in high-resolution aerial images: a review

“…have been detected (Gillette et al. , , McCafferty ). The automated‐detection method used by Christiansen et al.…”

Estimating sightability of greater sage-grouse at leks using an aerial infrared system and N-mixture models

“…previous aerial infrared studies of lekking grouse that also reported correlations between infrared cameras and ground counts (Gillette et al 2013(Gillette et al , 2015. However, we extend this study to provide robust estimates based on actual proportion of grouse counted from the aircraft relative to a 'true' number on the ground.…”

“…Furthermore, AIRIS can also be used to assess the accuracy of GBV counts, as we demonstrate in this study. Although past studies have compared similarities between counts recorded with infrared cameras to those collected on the ground for sharptailed grouse Tympanuchus phasianellus and sage-grouse (Gillette et al 2013(Gillette et al , 2015, sightability of newer AIRIS has not been formally estimated.…”

Approaches to delineate greater sage‐grouse winter concentration areas

“…Prevailing conditions, primarily changes in snow coverage and potential snow burrowing by sage-grouse at night, led to some deviations in standard flight protocols (J. P. Romero, personal communication), which precluded us from adding a detection component to our study design. The infrared flights produced similar counts of sage-grouse during spring lek surveys compared to ground-based observers (Gillette et al 2013); however, spring lek surveys occurred at known sage-grouse leks, allowing the pilot to home in on a specific location where grouse were likely to occur. Although not incorporating detection likely added some bias to our analyses, we standardized the data within our analyses as best as possible by including only daytime detections during conditions verified to work during our study.…”

“…We assumed that detection was similar across survey transects. We feel this was a reasonable assumption during the day given the ability of infrared to accurately count prairie grouse at leks (Gillette et al , ). There is a paucity of information on the makeup of winter sage‐grouse flocks, but available information suggests that individuals in winter flocks are often located within 200 m of each other (Beck ).…”