Leach's Storm-Petrel Identification

Overview
ID info
Life History
Maps
Sounds

Identification
Photo Gallery
Similar Species

Leach's Storm-Petrel Photos and Videos

A small seabird with long, angular wings, a strongly notched tail, and a broad pale “carpal bar” making a diagonal line across the wing and contrasting with brownish upperparts. Most populations have a white rump with a dark line running through the middle, though this line can be difficult to notice at distance.

In flight, note long, angled wings with a pale carpal bar running diagonally from the leading edge to the trailing edge.

A medium-sized storm-petrel with a distinctive bouncy, erratic flight. Note also the pale carpal bar, white rump (with dark dividing line just visible at times in this video), and notched tail.

The dark-rumped “Chapman’s” subspecies group breeds only on a few islands off the coast of Baja California and ranges north to waters off the California coast. Note the long, angled wings, pale carpal bar, and notched tail.

Normally occurs over deep ocean waters far from land. Forages by hovering and then picking individual prey items (fish and crustaceans) from the water surface.

Often best detected and identified at sea by erratic, bounding flight style, which is reminiscent of a Common Nighthawk.

(with Wilson's Storm-Petrel)

Often forages alone or in small groups but also joins flocks of other storm-petrel species, including Wilson’s Storm-Petrel and Wedge-rumped Storm-Petrel.

See more images of this species in Macaulay Library

Compare with Similar Species

Click on an image to compare

Wilson's Storm-Petrel

Band-rumped Storm-Petrel

Wedge-rumped Storm-Petrel

Townsend's Storm-Petrel

Looking for ID Help?

Our free app offers quick ID help with global coverage.

Try Merlin Bird ID

Identification

Fairly large, long-winged storm-petrel with deeply notched tail. Complex and subtle variation across extensive range. Typical flight style is somewhat bat-like: bounding with jolting twists and turns. Plumage looks chocolatey-brown in good light; paler than Wilson's or Band-rumped Storm-Petrel and with more extensive buffy bar on upperwing. Rump color is variable; birds in the Atlantic have a mostly white rump, usually with a thin dark line down the center. Pacific birds are more variable, sometimes completely dark-rumped, especially "Chapman's" Storm-Petrel (southern California to South America). Occurs in the Pacific and Atlantic Oceans, mainly in the Northern Hemisphere. Fairly common but stays far offshore; rarely seen from land.

Relative Size

Slightly larger than Wilson's Storm-Petrel and slightly smaller than Black Storm-Petrel. About the same size as a Least Tern.

Size chart showing sparrow to goose sized

between sparrow and robin

Measurements

Both Sexes
- Length: 7.1-8.7 in (18-22 cm)
- Weight: 0.9-2.5 oz (25-69.5 g)

Regional Differences

Ornithologists recognize two Leach’s Storm-Petrel subspecies groups: a widespread “Leach’s” group and a range-restricted “Chapman’s” group. The “Leach’s” group breeds in the North Atlantic and North Pacific and spends the nonbreeding season in the tropical Atlantic and central and eastern Pacific. The “Chapman’s” group breeds only on the Coronado and San Benito islands off the coast of Baja California. Birds in the “Leach’s” group generally have a white rump divided by a dark line, but dark-rumped individuals are increasingly common in the southern parts of the group’s eastern Pacific breeding range. Birds in the “Chapman’s” group usually have a dark rump. Birds in the “Leach’s” group have pointed wingtips and a shallower tail notch than birds in the “Chapman’s” group, which have somewhat rounded wingtips.