Multiple management strategies exist to combat bird damage to agriculture. We explored combining two tools, drones as frightening devices and an avian repellent, to assess effectiveness of an integrated method to deter large flocks on complex landscapes. We evaluated the ability of a spraying drone (DJI Agras MG‐1P) deploying Avian Control (i.e. active ingredient: methyl anthranilate; hereafter MA) or water to elicit abandonment, flock reductions, latency to return, and behavioral changes of blackbirds (Icteridae) foraging in sunflower Helianthus annuus. Following hazing and spraying (MA = 32; water = 32 trials), the percent of flocks abandoning, partially abandoning, or remaining was 56%, 31%, and 13% for MA and 50%, 25%, and 25% for water, respectively. Following full abandonment, 14% more flocks returned following MA (83%) than water (69%), averaging 3.96 min ± 3.51 (SD) to return (MA = 4.12 min ± 4.03; water = 3.73 min ± 2.68). When reduction occurred, average decline was 47% ± 35 (SD) with MA and 44% ± 39 (SD) with water. Site conditions impacted the ability to maneuver the drone and observe flock behaviors, potentially resulting in variables other than treatment explaining the probability of abandonment and flock reduction. When controlling for flock size, number of lift‐offs following water treatments (0.23 min−1 ± 0.17 SD) was statistically less than the pre‐hazing period (0.43 min−1 ± 0.28 SD), however no relationship existed for MA treatments (post: 0.29 min−1 ± 0.32 SD; pre: 0.31 min−1 ± 0.20 SD). This difference may be due to a longer latency to return, decreasing the post‐hazing time period, or flightier birds after MA exposure. We found eight mins of hazing, and a 9‐l tank of repellent, was insufficient to elicit differences between water and repellent applications. We suggest extended hazing or additional negative stimuli (e.g. multiple drones, increased repellent) to increase efficacy.
