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title: "Radar studies show Hawaiian Petrel and Newell's Shearwater numbers are decreasing"
---

# Radar studies show Hawaiian Petrel and Newell's Shearwater numbers are decreasing

André Raine ([Kaua‘i Endangered Seabird Recovery Project](http://kauaiseabirdproject.org/), Hanapēpē, Kaua‘i, Hawaii, USA) and colleagues have published in the journal *Condor* on declining population trends of [globally Vulnerable](http://datazone.birdlife.org/species/factsheet/22698017) Hawaiian Petrels *Pterodroma sandwichensis* and [globally Endangered](http://datazone.birdlife.org/species/factsheet/22698240) Newell's Shearwaters *Puffinus newelli*on the Hawaiian island of Kaua’i.

 The paper’s abstract follows:

 “The island of Kaua‘i, Hawaii, USA, holds a large breeding populations of the endangered Hawaiian Petrel (*Pterodroma sandwichensis*) and a majority of the world population of the threatened Newell's Shearwater (*Puffinus newelli*). We evaluated island-wide population trends of both species. For Newell's Shearwaters, we considered radar counts at 13 sites between 1993 and 2013 and annual island-wide tallies of fledglings retrieved after being grounded by light attraction in 1979–2015 (Save Our Shearwaters [SOS] program). For Hawaiian Petrels, we considered radar counts alone. Radar data indicated a 78% decline overall in numbers of Hawaiian Petrels (at an average rate of ∼6% per year) and a 94% decline overall in numbers of Newell's Shearwaters (at an average rate of ∼13% per year) during the survey period. Most (92%) radar sites showed significant declines of Newell's Shearwaters across the entire survey period, as did 62% of sites for Hawaiian Petrels. The SOS recovery effort collected 30,522 Newell's Shearwater fledglings between 1979 and 2015. When we compared this dataset in pre- and post-Hurricane Iniki (September 1992) periods, we found a significant downward trend after Hurricane Iniki, similar to the trend seen in the radar data. The large-scale declines found in this study are not surprising, considering the significant threats facing both species on Kaua‘i, which include powerline collisions, light attraction, introduced predators, and habitat modification - threats which were potentially exacerbated after Hurricane Iniki. Improved conservation initiatives and an increased understanding of the various threats facing the 2 species are key to reversing these declines.”

 ![Newells Shearwater release Elizabeth Ames s](https://www.acap.aq/images/stories/acap/Birds/Shearwaters/Shearwaters/Newells-Shearwater-release-Elizabeth-Ames-s.jpg)

 A Newell's Shearwater fledgling downed by lights gets released, photograph by Elizabeth Ames

 Read more [here](https://www.islandconservation.org/hawaiian-petrel-newells-shearwater-decline/) and [here](https://www.hakaimagazine.com/article-short/lights-out-hawaiis-seabirds).

 **Reference:**

 Raine, A.F.,Holmes, N.D.,Travers, M.,Cooper, B.A. & Day, R.H. 2017.  Declining population trends of Hawaiian Petrel and Newell's Shearwater on the island of Kaua‘i, Hawaii, USA. [*The Condor* 119: 405-415](http://www.americanornithologypubs.org/doi/abs/10.1650/CONDOR-16-223.1?code=coop-site).

 *John Cooper, ACAP Information Officer, 20 June 2017*