New England Seabirds
Leach's Storm-petrel photographed by Scott Surner on BBC
2011 Pelagic to Continental Shelf Edge.
Northern Hemisphere Breeder
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.
birds winter off the coast of Brazil. Occurs in all three
oceans: Atlantic, Pacific, and Indian.
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
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.
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
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
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.
Leach's Storm-petrels were feeding on
This really nice photo by
David Jones of Clamflats Photos.
See more of David's photos at
www.pbase.com/clamflats. Thanks for sharing.
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. Forked tail is very visible,
but notice that you do not see the dark band dividing
the white rump patch. The light band on the upper wing
certainly reaches the leading edge.
Photograph by Jeremiah Trimble of
two Leach's Storm-petrels from the June 2010 BBC
Continental Shelf Edge pelagic trip.
The forked tail is visible on the
right bird. The lack of wrapping of the white rump
patch is visible on both birds.
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
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
Does not follow in
the ship's wake. Occasionally follows trawlers (Harrison 2).
Attracted to beef suet chum floating on the water. 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
|Jeremiah Trimble photograph of
Leach's Storm-petrel sitting on the water.
||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.
These birds are Wilson's.
||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 3 legs are still
dragging below so they do not appear behind the tail. 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.
Can you identify the two
Storm-petrels in this photo by David Jones?
Left bird is
obviously a Wilson's Storm-petrel. Notice the feet
trailing the tail and the white bar on the wings
stopping short of the leading edge of the wing.
Right most bird appears to be a Leach's Storm-petrel.
Notice the white bar of the right wing reaches the
leading edge and the feet do not trail behind the tail.
Now how about this bird with the
obvious split white rump patch photographed by Eric
Masterson? Is this Leach's or Wilson's
the split white rump patch notice that the white wing
bar does not reach the leading edge of the wing, the
trailing edge of the wing is rather straight, and most
telling the feet trail the tail. This bird is a
Reference regarding Leach's Storm-petrel in the Pacific Ocean
2009 Howell, Steve ; McGrath, Todd;
Hunefeld, Terry; Feenstra, Jon Occurrence and
identification of the Leach's Storm-petrel (Oceanodroma
leucorhoa) comples off southern California North
American Birds Vol 63 (2009)- Number 4
STEVE N. G. HOWELL
• P. O. BOX 423,
BOLINAS, CALIFORNIA 94924
• 3550 ELM DRIVE,
CALABASAS, CALIFORNIA 91302 • (CORRESPONDING AUTHOR:
W. TERRY HUNEFELD
• 105 NORTH VULCAN
AVENUE, ENCINITAS, CALIFORNIA 92024 • (THUNEFELD@GMAIL.COM)
JON S. FEENSTRA
• 566 SOUTH FAIR
OAKS AVENUE, SUITE 108, PASADENA, CALIFORNIA 91105 • (FEENSTRA@ALUMNI.CALTECH.EDU)