SPECIES

Pink-footed Shearwater Ardenna creatopus Scientific name definitions

Ryan D. Carle, Valentina Colodro, Jonathan Felis, Joshua Adams, and Peter J. Hodum
Version: 2.0 — Published April 9, 2022

Identification

Field Identification

A large (length 45–50 cm, wingspan 109–118 cm, mass 576–889 g; 1, 2), polymorphic, grayish to brown, pale-bellied procellarid with a pale pink bill. In Definitive Basic Plumage it has a gray-brown cap that extends below the eye (occasionally with a narrow, pale, partial eye-ring). The brown coloration extends along the back to the mantle and scapulars, where it often appears scaly. The scaling also occurs on the rump and the uppertail coverts. Most of the upperwing is brownish, with darker shading on the remiges, tertials, lowermost scapulars and tail. The upper tail is blackish brown. The underwing is largely dark gray on exposed remiges, forming a trailing edge that is broader at the wingtip; otherwise it is white with variable dark markings. The palest individuals have mostly white coverts streaked and spotted dark on the carpal, on the basal half of the leading edge and the axillaries. The greater coverts usually have subterminal spots, and the darkest birds (< 0.1% of population; 2) have white predominating only on the central band (median coverts). The outer primaries and rectrices are narrower and more tapered or pointed at the tips than respective basic feathers, and the longest axillar is narrower and averages more whitish (3). The face is overall brownish-gray in coloration, with fine brown speckles on the lower face and whitish on the chin and throat. Demarcation of grayish neck, and sides is slightly more clearly cut from the white abdomen, with gray-brown speckling on rear flanks and vent and more solidly gray-brown on thighs and undertail coverts. The iris is blackish brown. The bill is pinkish to pale-pink, with dusky gray on the tip and sometimes on the culmen. Legs and feet are pink, and the outer toes can have a grayish tinge.

The sexes are similar, but females average slightly smaller in most measurements (4, 1). Juvenile and adult plumage are the same, but juveniles are in fresh plumage in May–July when older birds are in worn plumage or molting, making it possible to differentiate them (2).

Similar Species

In all but the rare, darkest morphs, Pink-footed Shearwater can be separated from the closely related Flesh-footed Shearwater (Ardenna carneipes) by the former species' dull-white abdomen and grayer upperparts (1,3,2). Dark-morph Pink-footed Shearwater is also grayer (less brown) than Flesh-footed Shearwater and usually shows a duskier pink bill and a hint of the pale underparts unlike the uniform brown underparts of Flesh-footed Shearwater (3). Wedge-tailed Shearwater (Ardenna pacifica) can resemble the palest Pink-footed Shearwater, but it is smaller and slimmer, with a smaller head, thinner and longer bill and tail, and a dull grayish rather than a pinkish base to the bill. Very pale individuals of Pink-footed Shearwater can also be confused with Buller's Shearwater (Ardenna bulleri), but the latter species is smaller, brighter white below, darker-capped, and with more narrow wings and more buoyant flight (2).

Although geographically separated for the most part, Pink-footed Shearwater can also resemble Calonectris shearwaters in appearance, flight action , and foraging habits. Compared to Calonectris species, Pink-footed Shearwater has a more pinkish bill, lacks U-shaped white marking at the tail base, and has dark markings on the axillaries and rearmost of underparts. Great Shearwater (Ardenna gravis) has a cap, with a dark bill and white at the tail base whereas Cory's Shearwater (Calonectris diomedea) has a yellowish base to the bill and nearly entirely white underparts and underwing coverts. Both of these species occur as rare vagrants off the West Coast of North America, overlapping the range of Pink-footed Shearwater (5, 6).

Recommended Citation

Carle, R. D., V. Colodro, J. Felis, J. Adams, and P. J. Hodum (2022). Pink-footed Shearwater (Ardenna creatopus), version 2.0. In Birds of the World (P. G. Rodewald and B. K. Keeney, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.pifshe.02