Abstracts

Presented by Roald Stander - Email: roaldstander@gmail.com

In less than 10 years since the release of the first commercially available Unmanned Aerial System (drone), their use has become widespread in wildlife research in both optical and thermal applications, but no published studies examine the use of a drone and thermal camera as a nest searching method for upland nesting waterfowl. Chain-drags are considered the traditional method for upland nest searching but are field intensive in terms of personnel, time and logistics, and on occasion can cause damage to the nest and possible adult mortality. We compare the efficacy and efficiency of a drone with a thermal camera as a new method for upland nest searching to the traditional chain-drag method in North Dakota. Using a drone we searched at night between 0205 h 20 min and 0519 h 53 min with semi-automated programming to survey 25 sites, totaling 247 hectares. Total time required to complete drone searches (n = 25) with ground verification (n = 24) averaged 26. 8.7 min/ha and chain drags (n = 25) averaged 13.1 7.3 min/ha. We found a total of 156 nests using both search methods, 80 were unique to the chain-drag (122 total nests), 34 were unique to the drone (76 total nests) and 42 were found by both methods. Detection rate for the chain-drag method were 55%, 95% CIs [0.44, 0.66] and 34%, 95% CIs [0.27, 0.43] for the drone method. Chain-drags resulted in one recorded hen mortality and seven incidents where a nest was partially or completely destroyed. Zero incidents were recorded during drone searches or ground verifications following those flights. Our research indicates that this specific drone system does not replace the chain-drag method, but can be utilized to conduct nest searches in habitats where ATV access is limited, or where the risk of mortality may be a concern.