Bulwer's Petrel

Bulweria bulwerii




Petrels and Shearwaters (Procellariidae)

Code 4


Code 6



Egg Color:


Number of Eggs:


Incubation Days:


Egg Incubator:

Both sexes

Nest Location:

In burrow or rock crevices.

Nest Material:

Leaves, stick and pebbles.





Bulwer's Petrel: Medium-sized petrel, dark brown overall with paler fringes on the greater and outer median upperwing coverts that form pale, diagonal bars across secondary coverts; sometimes is darker on the head and gradually gets paler on the chin. Long tail is usually held in a point; wedge shape visible only when fanned; long wings. Bill is black; legs and inner base of feet are light pink, dark gray on the rest of the feet. Sexes are similar; male has a longer bill and tarsus. Juvenile is similar to adult.

Range and Habitat

Bulwer's Petrel: This species breeds on small oceanic islands and offshore islets in the tropical Pacific and Atlantic oceans; it is an accidental summer visitor off Monterey, California, and the Outer Banks region of North Carolina. This species is highly pelagic, coming ashore only during its breeding season.

Breeding and Nesting

Bulwer's Petrel: They breed in dense colonies. The nest site is in a burrow under tree roots or rocks, or in a cave or rock crevice. Both sexes help dig the burrow. The nest chamber is lined with leaves, twigs and pebbles. One white egg is laid in a burrow or rock crevice. Incubation is carried out by both parents for roughly 51 days.

Foraging and Feeding

Bulwer's Petrel: These petrels feed on squid, plankton and small fish. They land on the water and are apparently opportunistic, taking any prey item occurring in surface waters. They do not plunge or dive. They sit on the water with wings spread and dip their heads below the surface. They generally feed alone, or occasionally in association with other birds.


Bulwer's Petrel: On breeding grounds makes a staccato monotonous "uh-uh-uh-uh" that sounds like a small motor running; usually silent at sea. Also makes a repeated series of "woof" notes lasting for several minutes.

Similar Species

Bulwer's Petrel: Flesh-footed and Short-tailed Shearwaters are larger.

The area of the face just below the bill.
The tarsus is the part of the leg between the knee and the foot of the bird, similar to the lower leg in humans.
The pelagic is a type of bird whose habitat is on the open ocean rather than in a coastal region or on inland bodies of water (lakes, rivers). An example of a pelagic bird is the blacklegged kittiwake.
Parts of a Standing bird X
Head Feathers and Markings X
Parts of a Flying bird X