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| Seabirds | Storm-petrels | Leach's Storm-petrel | Search | Comments | Site Map |
Leach's Storm-petrelOceanodroma leucorhoa |
 Leach's Storm-petrel by Glen Tepke and used with his permission. All photographs on this page remain the property of the photographer. |
Northern Hemisphere Breeder
Leach's Storm-petrel like
all Ocenodroma is a Northern hemisphere breeder and therefore is busy during
our summer. Migrates south during our winter.
In the north Atlantic
breeds on offshore islands from Maine, Canada, Nova Scotia, and Newfoundland. A few
pairs breed on Penikese Island south of Cape Cod. Regularly seen
in Cape Cod Bay during the summer. Take the Plymouth or
Barnstable whale watch. Also in Greenland and at St. Kilda
in Scotland.
In the north Pacific breeds on
offshore islands from Japan to the Aleutians and Alaska and south to the Baja
Peninsula.
Winters
Atlantic birds winter off the coast of
Brazil. Occurs in all three oceans: Atlantic, Pacific, and
Indian.
Nesting
Leach's lays a single egg in shallow burrows 1
-3 feet in length. Both parents take turns incubating and both feed the chick,
coming and going from the burrow only at night. Burrows can be collapsed by
humans walking about over them and nests are disturbed by dogs and
feral
cats.
Young are fed by both parents by regurgitation.
When To
See
Immature non-breeding birds can be seen offshore on the edge of the
Continental Shelf and at Cashes Ledge in summer. Late fall, especially October,
any Storm-petrel on Stellwagen Bank should be closely examined as it is
probably Leach's rather than Wilson's Storm-petrel. Also seen from seawatches
on Cape Cod during late fall and early winter. This bird is
perhaps easier to see on west coast pelagics.
Hard to observe on the
breeding grounds as it enters and leaves burrows at night and human presence
disturbs nest by collapsing burrows.
| Identification Similar plumage to Wilson's Storm-petrel. Leach's is larger and has a forked tail. See the photograph by David Jones to the right. This photo was taken on the 2010 BBC pelagic south of Cape Cod. A small vertical dark band dividing the white rump is visible in this photo may not be visible on all birds. This dark divider is variable by age and subspecies. See the article in American Birds. Legs do not trail behind the tail when flying. Bill, legs and feet are black. White rump patch does not extend down around the rump. Light band on wing reaches the leading edge of the wing.See pictures below. These characteristics are hard to observe at sea. Appears longer winged, has a slower wing beat, and you do not see the legs trailing behind tail. Notice that the trailing edge of the wing has a definite angle. Wilson's shows a straight trailing edge.
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 This really nice photo by David Jones of Clamflats Photos. See more of David's photos at www.pbase.com/clamflats. Thanks for sharing. |
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Photo by Eric Masterson on Cashes Ledge August 2009. Note forked tail and the light band that reaches the leading edge of the wing. |
Photographed by Eric Masterson on
Fippenes Ledge June 2010. |
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Two pictures of Leach's Storm-petrel taken by Glen Tepke. Both pictures show that the white rump patch does not extend down the sides of the rump. Notice the broad upper wing crescentic bars that reach the leading edge of the wing. Thanks for sharing Glen. With hundreds of Wilson's Storm-petrels around a boat, Leach's can be picked out because of the slightly larger size, different wing shape, and different flight characteristics. However, one pass near the boat is all you get and it is hard to point out to the novice birder
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Does not follow in the ship's wake. Occasionally follows trawlers (Harrison 2) which means it could be attracted by chum. Not as likely to patter feet on the surface of the water as Wilson's Storm-petrel. In light winds feeds by sitting on the water and moving forward using legs. (Flood and Thomas in British Birds 28 )
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This photo by Eric Masterson
taken in August on Cashes Ledge shows a mixed flock of
Wilson's and Leach's Storm-petrels feeding on the
surface. Eric called this photo 180 and it demonstrates
the value of photographs in identifying storm-petrels. The birds pattering on the surface are most likely Wilson's Storm-petrels while the birds sitting on the water are probably Leach's. The bird sitting just to the right of the center of the photo is most certainly a Leach's. Notice that it looks larger. The bird in the air over this bird also appears to be a Leach's because the tail appears notched and the broad upper wing crescent-shaped bar reaches the leading edge. This bar does not reach the leading edge of the left most bird nor the bird second from the top. |
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Photo by Eric Masterson taken in
August on Cashes Ledge Numbering the birds from left (1) to right (4). Bird 1 is possible 2 birds. Bird 2 is a Wilson's because the legs clearly trail the tail. Bird 3 is Wilsons ( light band on wings does not reach the leading edge, tail not forked). Bird 4 appears to be Leach's. (Forked tail, white rump patch does not wrap, legs do not trail.) Identification by Emmalee Tarry who readily admits to being wrong before. |
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