Sooty Tern Life History

Habitat

Sooty Terns occur in the tropical and subtropical waters of the Atlantic, Pacific, and Indian Oceans. They breed on remote atolls and cays composed of sand, coral, or rock, and typically nest in flat, open areas with limited vegetation. During the nonbreeding season, Sooty Terns are completely pelagic, remaining at sea far from land.

Food

Sooty Terns feed mainly on small fish and squid. They frequently forage above schools of predatory fish, especially tuna, which drive smaller fish to the ocean surface. Unlike most temperate terns (e.g. Common Tern), Sooty Terns do not plunge-dive to catch food. Instead, they pluck prey from at or near the ocean surface while remaining in flight, or by briefly touching down on the water before quickly taking flight again. They also catch flying fish in the air.

Nesting

Nest Placement

Nest site is typically in flat, open areas with limited vegetation, occasionally under bushes.

Nest Description

Either a shallow scrape or no nest at all, with egg laid directly on bare sand or rock. Incubating birds sometimes add pebbles or small pieces of vegetation to the nest site.

Nesting Facts

Behavior

Sooty Terns are highly social birds, typically feeding in flocks of tens to thousands of birds and nesting in large colonies with thousands of pairs (and occasionally up to a million pairs). Pairs are monogamous within a breeding season; some pairs renew their bonds in successive seasons, while others establish new pairings. Both sexes incubate a single egg and care for the chick. Adults and young birds leave the breeding colony shortly after the young begin flying. Since Sooty Terns do not breed until they are 4–10 years old, the young birds spend the next several years at sea. Away from breeding colonies, Sooty Terns are highly aerial in nature—they never come to land and essentially never rest on the ocean water. They may rest on floating debris or on the backs of surfaced sea turtles, but their feathers have little waterproofing, preventing them from resting on the water.

Conservation

The International Union for Conservation of Nature lists Sooty Tern's conservation status as Least Concern and estimates the global population size at 23 million mature individuals.

Credits

Bird Banding Laboratory. North American Bird Banding Program Longevity Records. Version 2023.2. Eastern Ecological Science Center. US Geological Survey. Laurel, MD.

BirdLife International. 2020. Onychoprion fuscatus. The IUCN Red List of Threatened Species 2020: e.T22694740A168895142. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T22694740A168895142.en.

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

Jaeger A, Feare CJ, Summers RW, Lebarbenchon C, Larose CS and Le Corre M (2017) Geolocation Reveals Year-Round at-Sea Distribution and Activity of a Superabundant Tropical Seabird, the Sooty Tern Onychoprion fuscatus. Front. Mar. Sci. 4:394. doi: 10.3389/fmars.2017.00394

Pratt, H.D., Bruner, P.L. and Berrett, D.G. (1987). A Field Guide to the Birds of Hawaii and the Tropical Pacific. Princeton Univ. Press, Princeton, New Jersey.

Reynolds SJ, Wearn CP, Hughes BJ, Dickey RC, Garrett LJH, Walls S, Hughes FT, Weber N, Weber SB, Leat EHK, Andrews K, Ramos JA and Paiva VH (2021) Year-Round Movements of Sooty Terns (Onychoprion fuscatus) Nesting Within One of the Atlantic’s Largest Marine Protected Areas. Front. Mar. Sci. 8:744506. doi: 10.3389/fmars.2021.744506

Schreiber, E. A., C. J. Feare, B. A. Harrington, B. G. Murray Jr., W. B. Robertson Jr., M. J. Robertson, and G. E. Woolfenden (2020). Sooty Tern (Onychoprion fuscatus), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.sooter1.01

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