Post-release survival of fallout Newell’s Shearwater fledglings from a rescue and rehabilitation program on Kauaʻi, Hawai‘i

Endangered Species Research
By: , and 



Light attraction impacts nocturnally active fledgling seabirds worldwide and is a particularly acute problem on Kaua‘i (the northern-most island in the main Hawaiian Island archipelago) for the Critically Endangered Newell’s shearwater Puffinus newelli. The Save Our Shearwaters (SOS) program was created in 1979 to address this issue and to date has recovered and released to sea more than 30500 fledglings. Although the value of the program for animal welfare is clear, as birds cannot simply be left to die, no evaluation exists to inform post-release survival. We used satellite transmitters to track 38 fledglings released by SOS and compared their survival rates (assessed by tag transmission duration) to those of 12 chicks that fledged naturally from the mountains of Kaua‘i. Wild fledglings transmitted longer than SOS birds, and SOS birds with longer rehabilitation periods transmitted for a shorter duration than birds released immediately or rehabilitated for only 1 d. Although transmitter durations from grounded fledglings were shorter (indicating impacts to survivorship), some SOS birds did survive and dispersed out to sea. All surviving birds (wild and SOS) traveled more than 2000 km to the southwest of Kaua‘i, where they concentrated mostly in the North Pacific Equatorial Countercurrent Province, revealing a large-scale annual post-breeding aggregation zone for fledgling Newell’s shearwaters. While there was reduced survival among birds undergoing rehabilitation, SOS remains an important contribution toward the conservation of Newell’s shearwater because a proportion of released birds do indeed survive. However, light attraction, the root cause of fallout, remains a serious unresolved issue on Kaua’i.

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Publication type Article
Publication Subtype Journal Article
Title Post-release survival of fallout Newell’s Shearwater fledglings from a rescue and rehabilitation program on Kauai, Hawaii
Series title Endangered Species Research
DOI 10.3354/esr01051
Volume 43
Year Published 2020
Language English
Publisher Inter-Research
Contributing office(s) Western Ecological Research Center
Description 12 p.
First page 39
Last page 50
Country United States
State Hawaii
Other Geospatial Kaua'i
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