The Sargasso Shearwater is the smallest of the shearwaters that visit North America. They can be found in tropical waters of the Indian, Atlantic, and Pacific Oceans, strongly preferring warm water areas. In the United States, they are found in the Gulf of Mexico, as well as the East Coast, where they are typically found far from shore, foraging over the warm waters of the Gulf Stream in the late summer and early fall when water temperatures are at their highest. Unlike some other Shearwater species, they are typically found foraging by themselves. They also do not often follow fishing vessels for scraps, as some shearwaters do. The species was formerly known as "Audubon's Shearwater".
Habitat
Nests on islands in scattered locations throughout the tropics of the world, using rocky islands, islands with softer soil suitable for nest burrows, or vegetated islands that offer protected spots for ground-nesting. Outside of the breeding season, they can be found in warm waters in most of the world's oceans.
Diet
Feeds mostly on small fish and squid.
Behavior
Forages by diving under the ocean's surface and swimming underwater after prey. They will also sometimes swim and grab prey at or near the ocean's surface.
Nesting
Nests in a underground burrow, in a crevice in rocky area, or on the ground in dense vegetation. The nest itself is either non-existent or a very sparse collection of vegetation and debris. The female lays a single egg, and both the male and female help to incubate it. After it hatches, both parents tend to the nestling.
Interactive eBird Map
Click to access an interactive eBird Map of Sargasso Shearwater sightings
Song
Usually silent, but will occasionally give a high-pitched whining call.
Migration
Widespread distribution, with birds breeding in the Caribbean, the western and Central Pacific, and the Indian Oceans. Outside of the breeding season, they range widely across warmer waters throughout much of the world.
Similar Species
In range, most likely to be confused with the Manx Shearwater.
Status
Populations are large, spread over a wide geographic area, and appear to be stable. The IUCN has listed the Sargasso Shearwater as a species of "Least Concern".
Further Information
- eBird - Sargasso Shearwater
- Audubon Field Guide - Sargasso Shearwater
- Cornell Lab of Ornithology - All About Birds: Sargasso Shearwater
Photo Information
Photo taken by Jason Forbes - Photo licensed under Creative Commons Attribution NonCommercial NoDerivs 2.0 Generic license.
