Friswold et al.: Targeted management of Wedge-tailed Shearwater 245 WEDGE-TAILED SHEARWATER ARDENNA PACIFICA FALLOUT PATTERNS INFORM TARGETED MANAGEMENT BROOKE FRISWOLD1*, KEITH SWINDLE2, DAVID HYRENBACH3 & MELISSA R. PRICE1 1Department of Natural Resources & Environmental Management, University of Hawai‘i at Mˉanoa, 1910 East-West Rd., Honolulu, HI 96822, USA (
[email protected]) 2United States Fish and Wildlife Service, 3375 Koapaka St., Honolulu, HI 96819, USA 3Hawai‘i Pacific University, 45-045 Kamehameha Hwy, Kˉane‘ohe, HI 96744, USA Received 17 January 2020, accepted 03 July 2020 ABSTRACT FRISWOLD, B., SWINDLE, K., HYRENBACH, D. & PRICE, M.R. 2020. Wedge-tailed Shearwater Ardenna pacifica fallout patterns inform targeted management. Marine Ornithology 48: 245–254. Seabird fledglings are often attracted to artificial, bright lights, leading to their grounding. This phenomenon is termed “fallout” and is associated with an increased risk of mortality from land-based threats. This study evaluated temporal trends and spatial factors, such as fallout clustering near lights and proximity to colonies, to inform targeted management actions. Standardized surveys were conducted from 2002 to 2010 for Wedge-tailed Shearwater Ardenna pacifica (WTSH) fallout on the island of O‘ahu, Hawai‘i, USA. First, yearly fallout counts along the transect showed a two-year cycle and identified 25 November as the date with the highest fallout across years. Second, artificial lights and utility lines were present in 94% and 83% of fallout locations, leading to significantly higher fallout rates at these locations compared to random points along the transect. Third, fallout decreased significantly as the distance from the colonies increased and was negligible farther than 5 km from the nearest colony.