Contents |   Seabirds   |   Colonies   |  Other Sea Life   |   Take a Trip   |   Trip Reports   |   Sources  |    TOP

New England Seabirds

 Wilson's Storm-petrel  Dave Jones

Seabirds

Storm-petrels Index
Wilson's Storm-petrel
Leach's Storm-petrel
Band-rumped Storm-petrel
White-faced Storm-petrel
European Storm-petrel
Separating NE Storm-petrels

Comments to webmaster

 

 

 Storm-petrels

Band-rumped Storm-petrel Complex

Band-rumped Storm-petrel
Oceanodroma castro
(Clements 2007 )

or
Grants[Band-Rumped] Storm-petrel
Oceanodroma [castro] undescribed
and
Madeiran[Band-rumped] Storm-petrel
Oceanodroma [castro] castro
(Howell 2012)

 

Band-rumped Storm-petrel Scott Spangenberg

 Band-rumped Storm-petrel photographed by   Scott Spangenberg on Cape Hatteras pelagic.6/6/04.

 

Taxonomy
There is much discussion about the taxonomy of what Howell (2012) calls the Band-rumped Storm-petrel Complex. This term is used for a group of birds initially recognized as a single species and then later separated into multiple subspecies or even full species.

History
Harrison (1983) considered the Band-rumped group to be one species which he called Madeiran Storm-petrel Oceanodroma castro. Only and Scofield (2007) used the same taxonomy.
Clements (2007) calls it Band-rumped Storm-petrel Oceanodroma castro and says it is found in both the Atlantic and Pacific Oceans.
Recent study has identified 9 different populations of the Band-rumped Storm-petrel.

Species Evolution
It has long been recognized that populations of a species which become isolated by geography will in time develop distinct gene pools and eventually become separate species. How about a species with two populations which share the same or neighboring geography but breed at different times of the year? Summer breeders disburse in fall and winter and that is when they might show up on our coast while winter breeders will show up in spring and summer.

This appears to be the case with the Band-rumped Storm-petrels that frequent the coast of North America. It is important to note the time of the year when sightings are made while we wait for further research to sort all this out. At the same time there is an opportunity for our trips to add to knowledge of this species.

A big boost to the observation of the Band-rumped Storm-petrel came on the August 2010 BBC offshore pelagic to the Continental Shelf when it was discovered that this bird will respond to small pieces of beef fat used as chum.

Two Species in North American Waters
Howell(2012) describes the two species (or subspecies) to be found in our warters. Both are found in warm, deep waters usually in the Gulf Stream.

Grant’s [Band-tumped] Storm-petrel Oceanodroma [castro] Latin name undescribed (1.)
Larger than Wilson’s Storm-petrel, legs do not trail beyond the tail when flying. Breeds October to March in the eastern Atlantic on the Azores, Berlangas, Canary Isalds, Maderian archipelago, and Selvages. Ranges at sea from May to August to warm waters of the western Atlantic and Gulf of Mexico.  (1) Notation copied from Howell (2012) and not explain in text.

Madeiran [Bandrumped] Storm-petrel Oceanodroma [castro] castro.
Madeiran breeds June to October from the Madeiran archipelago south to the Canary Islands. Its range at sea is not well known. In the introduction Howell says the Maderiran Storm-petrel is presumed to occur, but not yet confirmed.

Until both species are better studied it is probable that a bird seen in our waters is a Grant’s Storm-petrel. Careful notes on date observed and molt stage should be taken on any bird and photographs preserved.

How To See
Usually found offshore in warm Gulf Stream waters. In our area this means taking the August to September canyons strips sponsored by the Brookline Bird Club. In August 2004 this trip identified one Band-rumped Storm-petrel. Several were seen on the July 19, 2008 trip and also in August 2010. All in the warm water.from the Gulf Stream moving in the area. See the description of the continental shelf edge south of Cape Cod.

A better bet is to take an offshore pelagic trip from North Carolina.

Behavior
Patters feet on surface of water when feeding.
Feeds alone or in small groups. Attracted to chum and perhaps fish oil.

Separating from other Storm-petrels
New England birders need to separate Band-rumped from Wilson's and Leach's Storm-petrels.

Band-rumped depending upon the sub-species is generally larger than Wilson’s SP and the legs do not trail beyond the tail when flying as in Wilson’s Storm-petrel. The white rump patch does wrap around the sides of the body. If a photograph shows yellow webs between the toes it is a Wilson’s not a Band-rumped.

Tail is not deeply notched as in the Leach's Storm-petrel and the white patch which is not split by a dark line, wraps around to the lower part of the body..

Band-rumped Storm-petrel photographed by Jeremiah Trimble on the August 2010 BBC Pelagic.

Note that the feet do not trail behind the tail, the light bands on the wing almost but not quite reach the leading edge of the wing, the complete white rump, and the angle in the trailing edge of the wing.

These Band-rump Storm-petrels were feeding on cut up piece of beef fat. They picked up the fat from the water and flew off with it returning to the boat several times. This was the first time to the author's knowledge that this Storm-petrel responded to chum.

Thanks go to the people who run the Washington State pelagic for introducing the idea of using beef fat which floats as chum. Also to the webmaster for persuading reluctant New England birders that fat attracts more than Woodpeckers.

Awesome picture, Jeremiah. Thanks for sharing.

Band-rumped Storm-petrel Jeremia Trimble

Scot Spangenberg Band-rumped Storm-petrel photographed on 2008 BBC Continental shelf edge trip.l.

This picture shows the white rump patch that extends around the sides of body.

The light wing patch does not almost reach the leading edge of the wing. perhaps because the wing is extended.

Bill of the Band-rumped Storm-petrel is a bit larger than that of Wilson’s SP.

Band-rumped Storm-petrel  Scott Spangenberg
Photographers on pelagic trip

Big lenses
These photographers and many others are aiding the identification of Storm-petrels. The new cameras use digital film so that pictures of water can be discarded. Rapid shutter speed allow the photographer to hold down the shutter button and take a series photos as the bird flies by.

On a recent pelagic trip one of the ship mates remarked on the amount of optics (cameras and binoculars) on board. In wonder he speculated there was about $20,000 worth of equipment. My estimate was about 3 times that amount.

Thanks to all the excellent photographs the days of identification arguments some of which lasted for years are gone. As soon as the bird disappears the photographers start sharing at their photos.

Steve Mirick is the photographer on the far right. Thank you to all of them.

Seabirds | Storm-petrels  |  Wilson's SP |  Leach's SP  | Band- rumped SP  | White-faced SP  |  European SP  | Separating | Top of Page       Comments to webmaster

Clements, James F. (2007) The Clements Checklist of Birds of the World Cornell University Press Ithaca, New York

Harrison, Peter (1983) Seabirds an identification guide Houghton Mifflin Company; Boston

Howell, Steve N.G. (2012) Petrels, Albatrosses & Storm-petrels of North America A Photographic Guide Princeton University Press; Princeton