Newell's Shearwater Life History

Habitat

Newell's Shearwaters breed only in the main Hawaiian Islands. Their stronghold is on Kauai and they also nest on Molokai, Hawaii, Maui and possibly Oahu and Lanai. This species breeds at higher elevations (160–1,200 meters or 525–3,900 feet above sea level on Kauai) in burrows or deep rock crevices among dense vegetation. To avoid introduced mammalian predators like pigs, mongooses, rats, and cats, Newell’s Shearwaters now nest on steep slopes (28°–48°). They also use near-vertical volcanic crater walls on the island of Hawaii. Nesting sites on Kauai are among the rainiest places on Earth. At sea, this species forages over very deep ocean waters (more than 2,000 meters or 6,600 feet) with warm surface temperatures (averaging 26.8°C or 80.2°F).

Food

Newell's Shearwaters feed mainly on flying squid and flying fish that are pushed near the ocean surface by schools of predatory fish. After spotting prey or other foraging birds, these shearwaters make low-angle plunges into the water and then continue swimming after prey, propelling themselves with their wings. They can dive at least 50 meters (164 feet) deep and catch and eat more than one prey item in a single dive.

Nesting

Nest Placement

Pairs dig nest burrows or utilize rocky crevices in volcanic soil. Burrows average about 90 cm (35 inches) in length and are usually situated on very steep terrain with dense ferns and other ground cover. Pairs use the same burrows from year to year, even when the burrows are damaged.

Nest Description

A simple scrape, typically with some pieces of native vegetation added to the egg chamber.

Nesting Facts

Behavior

Newell's Shearwaters are strong, fast fliers, beating their wings rapidly with little gliding. They frequently fly into the wind, much more so than other shearwaters and large petrels. Newell's Shearwaters are skilled divers, plunging into the ocean at shallow angles and then using partially opened wings to propel themselves underwater. When foraging, small numbers of Newell's Shearwaters join other seabird species in flocks that follow tuna and other predatory fish.

This species breeds in colonies, where adults are active at night. Pairs are likely monogamous, as is the case with the closely related Manx Shearwater. The two pair members incubate the single egg equally and take turns feeding the nestling for 6–12 nights at a time. The chick fledges after about 13 weeks and is independent as soon as it leaves the nest.

Conservation

The International Union for Conservation of Nature lists Newell's Shearwater's conservation status as Critically Endangered based on a declining population estimated at 10,000–20,000 mature individuals. Declines are due to predation by introduced predators, habitat deterioration, and effects of urbanization. Newell’s Shearwater fledglings are often attracted to artificial lights once they leave the nest, resulting in “fallouts” in urban areas of Kauai and Maui, with young birds circling lights until exhausted or colliding with cars and powerlines. In response to these fallouts, a Save Our Shearwaters (SOS) program was established in 1978 to rescue and rehabilitate these fledglings. The U.S. Fish and Wildlife Service lists this species as Threatened under the U.S. Endangered Species Act.

Credits

Ainley, D. G., T. C. Telfer, M. H. Reynolds, and A. F. Raine (2020). Newell's Shearwater (Puffinus newelli), version 1.0. In Birds of the World (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.towshe2.01

BirdLife International. 2019. Puffinus newelli. The IUCN Red List of Threatened Species 2019: e.T132467692A152723568. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T132467692A152723568.en

Floyd, T. (2025). Field Guide to the Birds of the United States and Canada. Eighth edition. National Geographic Society, Washington, D.C.

Howell, S. N. G. (2012). Petrels, Albatrosses, and Storm-Petrels of North America: A Photographic Guide. Princeton University Press, Princeton, NJ, USA.

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