Post-collision impacts, crippling bias, and environmental bias in a study of Newell's Shearwater and Hawaiian Petrel powerline collisions

Tracy Anderson,Hannah E Moon,Shiho Koike,Scott Driskill,Molly Bache,Amy A Shipley,Marc S Travers,David M Golden,Theresa Geelhoed,Angela Stemen,Andre F Raine

doi:10.5751/ace-01841-160115

Abstract

Travers, M. S., S. Driskill, A. Stemen, T. Geelhoed, D. Golden, S. Koike, A. A. Shipley, H. Moon, T. Anderson, M. Bache, and A. F. Raine. 2021. Post-collision impacts, crippling bias, and environmental bias in a study of Newell's Shearwater and Hawaiian Petrel powerline collisions. Avian Conservation and Ecology 16(1):15. https://doi.org/10.5751/ACE-01841-160115

Highlights

Since seabird population trend monitoring began in 1993 on Kaua’i Hawaii, the Hawaiian Petrel (Pterodroma sandwichensis; ‘Ua’u in Hawaiian) and Newell’s Shearwater (Puffinus neweilli; ‘Ao’ in Hawaiian) have declined by 78 and 94% respectively (Raine et al 2017)
Observed collisions were detected in each of the months from May through September, with no collisions observed during the fledgling period. 108 of the 121 seabird collisions were observed with observation equipment that allowed for elevation loss tracking and improved post-collision outcome determination
Like Cooper and Day (1998), we too have observed many near misses at powerline sections that currently have a collision rate of zero, which includes observations of high-risk flights of seabirds flying directly between the wires

Summary

Introduction

Since seabird population trend monitoring began in 1993 on Kaua’i Hawaii, the Hawaiian Petrel (Pterodroma sandwichensis; ‘Ua’u in Hawaiian) and Newell’s Shearwater (Puffinus neweilli; ‘Ao’ in Hawaiian) have declined by 78 and 94% respectively (Raine et al 2017). Determining the causes of the decline is a critical conservation goal for these endangered Hawaiian endemics This is important because the majority of the world’s remaining Newell’s Shearwater population breeds on this single island (Cooper and Day 1998, Pyle and Pyle 2017, Ainley et al 2019) along with significant breeding populations of the Hawaiian Petrel population (Cooper and Day 1998, Pyle and Pyle 2017). A 1993-1994 study observing the behavior of seabirds crossing powerlines on Kaua’i identified a high-powerline collision risk (Cooper and Day 1998). In 1993 and 1994, separate grounded bird search studies showed that powerline collisions were a significant source of sub-adult and breeding adult Newell’s Shearwater mortality (Cooper and Day 1998, Podolsky et al 1998) and grounded bird data was subsequently used to estimate the overall impact of powerlines on Newell’s Shearwaters (Podolsky et al 1998)

Methods

Results

Conclusion