Actions to minimize light attraction of adult seabirds

Light attraction is a well–documented phenomenon affecting seabirds world–wide, but it is typically associated with fledglings.  There is little in the literature regarding the impact on breeding adult seabirds on land.  We document a large-scale fallout event of adult seabirds at a facility in the north-west of Kauaʻi.  In September of 2015, 131 adult endangered seabirds including 123 ʻaʻo (Newell’s Shearwater Puffinus newelli) and 6 ʻuaʻu (Hawaiian Petrels Pterodroma sandwichensis) were grounded by lights at the Kōkeʻe Air Force Station – the majority occurring over a two-night period.  This was caused by the proximity of the facility to large breeding colonies of the species coupled with bright, upward–facing, unshielded lights and nocturnal conditions that exacerbate the fallout phenomena - a waning moon (thus a dark night), with rain and fog.  In response to this event, the facility altered its lighting protocol to use only shielded low–intensity light bollards (amber (590nm) 33 watts LED).  Results from annual monitoring at the facility found only four grounded ‘a’o between 2016-2023 indicating that the new lighting regime dramatically reduced fallout.  We use the results of this study to provide recommendations for best–practice light minimization methods in similar situations worldwide.

Lights at the facility during the fallout were bright green, unshielded and often upwards facing. Photo: André F Raine.

Lights after minimization were significantly reduced, consisting of bollards emitting a low wattage amber glow (590mm, 33 watts). Photo: André F Raine.

Grounded 'a'o (Newell's Shearwater) often crawled into very small dark spaces and were only found by dedicated searchers using flashlights. Photo: André F Raine.

More info at: 
Raine AF, et al. 2024. The impact of light attraction on adult seabirds and the effectiveness of minimization actions. Pacific Science