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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


 

 

 

 

Storm-petrels

Wilson's Storm-petrel

Oceanites oceanicus

 

 

Comments to webmaster

 

 Wilson's Storm-petrel feeding on suet chum.  Scott Spangenberg

Signature Species
This web site is dedicated to Wilson's Storm-petrel and the site logo is a Wilson's Storm-petrel photographed by Dave Jones. The Storm-petrel is shown pattering its feet on the surface of the water while feeding on floating suet. A trip to Stellwagen Bank or almost any other canyon or bank in our area will see thousands of this delightful little bird vacationing in our northern seas. Unlike most other Storm-petrels it is a ship follower and a scavenger. The author has traveled to the breeding ground in Antarctica . At Brown Bluff on the Antarctic Peninsula a few birds were seen flying to and from the cliffs overhead. At sea we frequently saw an individual flying over the water. However nothing comes close to the thousands of these little birds swarming around the whale watching boats on Stellwagen Bank in the summer.

Furthermore in my travels with the exception of the flock of thousands of Least Storm-petrels roosting on the water on the fall 3 day San Diego pelagic, I have never seen such a dense show of Storm-petrels as we have in July and August. Don't miss this wonderful show and don't take it for granted. I do remember a summer when there were very few Wilson's Storm-petrels on Stellwagen Bank. Something must have happened to the food source that summer.

Southern Hemisphere Breeder
Two subspecies "O.o.oceanicus breeds in South Georgia, Crozets, Kerguelen, Falklands, Tierra del Fuego, islands off Cape Horn , and perhaps also at Peter, Balleny and Bouvet Islands.

O.o. exasperatus South Shetlands, South Sandwich , and most if not all suitable sections of Antarctic coastline." (Harrison 1983 )

In the Antarctic Peninsula nests in cavities in glacial rubble, scree, and also in tunnels excavated by the birds under boulders. Usually enters and leaves the nest site at night. One egg per nest. Both parents incubate the egg and feed the chick. Adults, eggs and chicks preyed upon by Skuas. (Harrison 1983). An even bigger danger is that the adult, egg, or chick become trapped in the burrow by a heavy snow storm. Researchers in Antarctica found mummified remains in burrows.

When To See
Look for Wilson's Storm-petrel from June to October on Stellwagen Bank and even in the harbor in summer. The highest numbers are seen in July and early August. The bird is best observed on very calm seas when you can see it pattering on the water picking up bits of food on the wing.

Identification - Dark with white rump
The first Storm-petrel you are likely to see in New England waters is the Wilson's Storm-petrel or WSP. The first characteristic you will notice is that it is a dark bird with a prominent white rump. Your identification problem will be to separate it from the three other dark with white rump Storm-petrels possible in our waters. Separating New England Storm-petrels.

In this awesome photograph taken by Scott Spangenberg you can see the primary field marks of the WSP.

The most prominent feature is the complete, white band on the rump. When flying the long legs trail behind the tail.(1). There are white bands on both upper wings that do not reach the leading edge of the wing. (2) Notice the straight trailing edge of the wings in calm winds.(3)

Wilson's Storm-petrel  Scott Spangenberg
Wilson's Storm-petrel under side Scot Surner

Underside
Scott Surner captured this view of Wilson's Storm-petrel which shows the underside as it banks toward the boat. Notice that the wings are dark underneath and that the white rump wraps on either side of the tail down to the legs. The bird's left leg clearly extends beyond tail.

Look closely at the right foot and you can see a hint of the yellow web between the toes.

The close approach of this Storm-petrel and the thousands that swarm in our waters makes photographs like this possible. Great picture Scott. Thanks for sharing.

Feet With Yellow Webs
Early field guides show Wilson's Storm-petrel with yellow webbing between the toes. This characteristic is almost never observed in the field without having the bird in hand as in this photo by Eric Masterson.

Modern field guides with the exception of the National Geographic Field Guide do not show this characteristic as it is not really a field mark. 

Two other Storm-petrels have yellow webs: White-faced Storm-petrel and Elliot's Storm-petrel found in the Humbolt Current in the south Pacific.

Using expensive film, we took many pictures of water trying to get good shots of these very active little birds. Digital photography changed everything. Photographers took to the sea on pelagic trips and whale watches with huge lenses, cameras that can take a series of rapid fire shots and digital pictures that can be quickly reviewed and stored or deleted. Photographers take hundreds of shots on each trip.

We began to get some wonderful pictures that clearly show the yellow webs. The first I received came from Arthur H. Kopelman president and sponsor of the CRESLI pelagics. He captured this awesome photograph of a Wilson's Storm-petrel at Veatch's Canyon, June 6, 2006. Not quite in focus he probably thought about discarding it until he noticed the yellow webs.He sent the first, but not the last.  The lesson here is that all photographs do not have to be perfect to be useful in identification and documentation.

Wilson's SP yellow webs Eric Masterson

Wilson's SP yellow feet Kopelman
Wilson's Storm-petrel yellow web Scott Spangenberg

Scott Spangenber donated this great photo of Wilson’s Storm-petrel from the July 19,2008 BBC Pelagic to the Continental Shelf edge,

The bird on the left has its feet closed as usual, but the bird on the right is caught with both feet open giving us a clear look at the yellow web. Nice photo Scott.

Yellow webs are not a field mark for the ordinary observer, but with a good photograph they are pretty definitive. The only other Storm-petrel in our area to display yellow web is the White-faced Storm-petrel which is otherwise very distinctive.

Notice also how clearly the white rump wraps around the underside of the bird to the left and the light band on the upper wing clearly stops short of the leading edge of the left wing.

Feeding
WSP Breed in the southern hemisphere and migrate to the north Atlantic in our summer to feed on copepods and small crustaceans which it sometimes picks from the surface of the water on the wing as you can see in this photograph by Jim Wallius. Notice the foot print on the water.

Feeds over the continental shelf. Follows ships and whales. Attracted to chum. A most birder friendly seabird. Known to feed on oil from carcasses. About 20 birds were observed feeding near the carcass of a Right Whale by the Newburyport Whale Watch just outside the mouth of the Merrimack River.

Notice the white band on the wing does not reach the leading edge of the wing.

WSP feeding Jim Wallius
Wilson's Storm-petrel Chris Ciccone

Behaviors
The most obvious Storm-petrel behavior is pattering their feet along the surface of the water when feeding. This is best observed on a calm ocean.

Observe the angle of the wings when pattering. Wilson's Storm-petrel holds its wing in a horizontal to a shallow V shape as seen in Chris Ciccone's photograph.


Usually found in groups either resting on the ocean or feeding.

Wilson's Storm-petrel  L Medlock

Wilson's Storm-petrel patters on the ocean surface with wings almost horizontal. Photographed by Leonard Medlock on the August 08 BBC Extreme Pelagic





Wilson's Storm-petrel J Slovin

One more picture of the yellow feet usually seen just as the bird takes off from the water.  The webmaster has seen untold thousands of WSP some of them very close to the boat, but not once have I seen the yellow webs between the toes. Thank you Jim Slovin for this wonderful picture.

 

The Right Storm-petrel To Watch
Wilson's is the Storm-petrel to watch as it readily approaches boats and can often be observed within 3 feet of the boat. Harrison says It follows ships and attends trawlers.(Harrison 1983) . Follows ships means it will follow the wake of a boat that is steaming along without dispersing fish waste or chum. Attends trawlers refers to gathering behind a fishing vessel discarding fish parts.


On my first pelagic trip to Monterey Bay in California, I was looking forward to identifying several new Storm-petrels. The first flock spotted was far from the boat almost to the horizon. I decided to wait for a closer flock. But the next flock was also far away as was the following flock and they didn't seem to respond to the boat's chumming. I realized that other storm-petrels are not boat followers and I had to work at identifying distant storm-petrels. That's when I came to appreciate our wonderful little bird watcher friendly Wilson's Storm-petrel.

West coast pelagic trips have started using beef suet as chum and are having more success at getting the Storm-petrels closer to the boat.  On a SOCAL over night trip a large flock of Black Storm-petrels and Fork-tailed Storm-petrels responded to suet that had been put through a hamburger meat grinder.  A large flock of Least Storm-petrels ignored the commotion.  On the Atlantic side, Band-rumped Storm-petrels that usually make a single pass by the boat and are gone also responded to suet that had been put  through a meat grinder. The birds made pass after pass over the suet. It is hard to get the butcher to grind suet for you, but you need very small piece of suet for the birds to pick up quickly as they fly over the water.

Dive?
Does Wilson's Storm-petrel dive? I have seen thousands of Wilsons and never saw a single bird dive under the water. Parmelee (1993) descrbes an incident of Wilson's Storm-petrel "submerging to grasp rising oil droplets before the droplets could float to the surface and burst."  I don't really consider that diving.

A bird that doesn't fly and a seabird that doesn't dive are the wonders of birdwatching.

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

Parmelee, David Freeland 1993 Antarctic Birds Ecological and Behavioral Approaches University of Minnesota Press; Minneapolis Oxford