Submitted to: Western North American Naturalist
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/15/2009
Publication Date: 9/23/2009
Citation: Booth, D.T., Cox, S.E., Simonds, G. 2009. Efficacy of Two Variations on an Aerial Lek-Count Method for Greater Sage-Grouse. Western North American Naturalist 69(3):413-416. Interpretive Summary: Use of a light, low-operational cost airplane and digital aerial photography has the potential to increase the number, accuracy, distribution, and frequency of annual counts used to census sage-grouse populations. We tested aerial-photography methods on 6 breeding display sites (leks) in Elko County, Nevada and found there is the potential to save about 4 person hours per lek per count, and that a greater number of leks can be monitored during the 1 to 2 post-sunrise hours when the birds are active—however, the birds fled the leks as the airplane approached. Although not successful, the information gained resulted in several ideas for improving future trials and are presented with the hope of advancing sage-grouse census methods.
Technical Abstract: Nine sage-grouse petitions, are currently filed with the US Fish and Wildlife Service for listing the sage grouse as a threatened species under the Federal Endangered Species Act. It is therefore important to improve the sage-grouse census methods for accuracy, frequency, and lek-count distribution. Despite susceptibility to bias and error, and the cost of time-consuming ground-observer counts, that remains the most practical means of estimating the breeding sage grouse population. A quick and accurate survey method utilizing a light airplane with low operational cost and digital camera would be of great benefit for increasing the number, accuracy, distribution, and frequency of annual lek counts. We tested this approach but ground observers at every lek reported: (1) birds on the lek prior to the fly-over, (2) a cessation of strutting upon first hearing the airplane, and (3) the birds fleeing the lek en masse when the airplane drew within 200-300 meters of the lek. Although our methods were not successful, we feel it fitting to present the results with information gained from our reviewers. Reviewer comment suggest that with appropriate changes in aerial lek approach, aerial methods might yet advance the art of sage-grouse census.