Efficacy of autonomous recording units to evaluate wild turkey gobbling chronology in North Carolina, USA

Abstract

AbstractWild turkey (Meleagris gallopavo) gobbling is a key component of hunter satisfaction, also providing insight into the underlying reproductive ecology of wild turkeys that can inform regulatory decisions. However, monitoring gobbling chronology over large geographic areas can be logistically challenging and identifying efficient monitoring schemes can help wildlife agencies better manage the species. We evaluated the efficacy and utility of autonomous recording units (ARUs) to detect wild turkey gobbles and deployed 51 ARUs to monitor gobbling chronology in North Carolina, USA. We conducted controlled field‐tests at 20 locations to compare how detection of gobbles differed by ARU software, manual review of ARUs, and in‐field human observers. Autonomous detections had the lowest probability, with detection probabilities approaching 0 at 300 m from the ARU. Autonomous detections of gobbles were affected by leaf‐on conditions and topographical interference while vegetation type surrounding ARUs had minimal and inconsistent effects on detection. We deployed ARUs on properties with little or no turkey hunting across North Carolina from March–May during 2016 through 2019 to explore annual and regional variation in gobbling chronology. We used ARUs to monitor gobbling chronology and recorded 53,943 hours of audio files from which we confirmed 113,737 gobbles out of a total of 602,053 possible sound events identified. We identified multimodal gobbling chronology across 3 primary physiographic regions in North Carolina. We also found comparable timing of gobbling chronology across the 3 regions, with 57–61% of gobbling occurring during the weeks in which hunting seasons occur. We recommend that researchers validate ARU performance to calibrate monitoring of gobbling chronology. Additionally, our gobbling chronology data suggest that a statewide framework, rather than a regionally split framework, is appropriate for wild turkey hunting in North Carolina.