Comparison of in-person and remote camera lek surveys for prairie grouse (Tympanuchus spp.)

Abstract

In-person lek count surveys are commonly used for estimating population size and trends for prairie grouse. However, the emergence of noninvasive camera trap survey methods holds promise for more cost-effective and precise estimates of lekking species. To evaluate the efficacy of using camera traps, we deployed a remote camera study at lekking grounds over 3 years in conjunction with in-person surveys. Our objectives were to 1) develop an effective remote camera survey for greater prairie-chickens (GRPC; Tympanuchus cupido) and sharp-tailed grouse (STGR; T. phasianellus), 2) compare metrics of male detection, maximum male counts, and male abundance estimates derived from in-person versus remote camera surveys, 3) assess lek activity over the survey season to inform survey timing, and 4) evaluate costs for each survey type. We found that in-person surveys resulted in maximum male GRPC and STGR counts. The estimated number of male GRPC and STGR on leks were comparable between in-person surveys and camera monitoring when accounting for detection probability with N-mixture models. Camera traps constantly monitored leks over the season which provided daily and seasonal activity patterns of prairie grouse. Total cost of GRPC remote camera surveys was higher than in-person surveys, but hourly cost was less ($0.77 vs. $160 per hour). Remote camera survey costs for GRPC were high because of time classifying photos which could be reduced by decreasing the amount of time remote cameras were operated or using automated classification software to remove blank photos. We believe the use of remote cameras could supplement in-person surveys for future lek monitoring and aid future survey efforts by identifying yearly differences in activity and presence at leks inconsistently visited by birds.