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

Diet and Foraging

Introduction

Pink-footed Shearwater feeds mainly on fishes and squids, though its diet is not well studied. It feeds mainly by surface-seizing, pursuit plunges, shallow dives, and scavenging, and is attracted to fishing boats where it may feed in flocks of 1,000s, sometimes with other shearwaters, albatrosses, and gulls. Flocks of up to approximately 100 birds may forage over schools of herring (Clupea), salmon (Oncorhynchus), albacore tunas, and Stenella dolphins. Usually forages in outer continental shelf and slope waters in both the breeding and nonbreeding ranges.

Feeding

Microhabitat for Foraging

Usually forages in outer continental shelf and slope waters in both the breeding and non-breeding ranges (45, 28, 29, 16). In outer continental shelf and slope waters off northern California and southern Oregon, foraging was associated with areas where other predators, such as salmon, were foraging (45).

In a study of 6 birds tagged with time-depth recorders and GPS devices from Isla Mocha, diving behavior occurred throughout the full extent of the breeding-period foraging area, and occurred most frequently within continental shelf waters near Valdivia, Chile (28). Diving also occurred within approximately 20 km of Isla Mocha and north of Isla Mocha from Lebu to north of Talcahuano, Chile (28), consistent with hot spots identified from a larger sample of GPS-tracked birds from Isla Mocha (29).

Food Capture and Consumption

As a group, shearwaters display variable modes of foraging including scavenging, surface seizing, shallow plunge-pursuits, "belly-flop" plunging, shallow diving, and deep diving (46, 47, 48, 49, 28). Although there are few written descriptions, Pink-footed Shearwater appears to feed mainly by pursuit-plunging and shallow wing-and-foot-propelled diving from the water surface or several meters above the water; prey are also taken by surface-seizing and scavenging (47). Mean dive-depth of tagged birds was 1.6 m ± 1.2 SD (maximum depth 10.1 m), and dives usually lasted < 6 seconds (28).

Attracted to fishing boats, where it may feed in flocks of 1,000s, sometimes associated with other shearwater species, albatrosses, and gulls (45, 2). Flocks of up to approximately 100 birds may forage over schools of Pacific herring (Clupea pallasii; K. Morgan, personal communication), salmon (Oncorhynchus spp.), other large fish (e.g., albacore tunas), and dolphins (50, 45, 2).

Diet

Major Food Items

Feeds mainly on fishes and squids (51, 52), though diet has not been received in-depth study. Documented prey species in the nonbreeding range include squids (Doryteuthis opalescens and Onychoteuthis borealijaponicus) and northern anchovy (Engraulis mordax; 52). In the South American breeding range, commonly associates with fisheries for Peruvian anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki; 53,29), indicating that these species are probable prey. Limited direct diet observations support this (PJH; C. Suazo, personal communication).

Quantitative Analysis

Stomach content analysis from 5 birds taken from September 1974 to April 1975 in Monterey Bay, California, indicated that squid (Doryteuthis opalescens and Onychoteuthis borealijaponicus) contributed 83% of the diet by number, with the remainder made up of northern anchovy (9%), and unidentified fishes and cephalopods (8%) (52). Doryteuthis opalescens occurred in 60% of stomachs, Onychoteuthis borealijaponicus in 40%, and northern anchovy in 60% (52). No quantitative data exist on diet in the Southern Hemisphere.

Food Selection and Storage

No information.

Nutrition and Energetics

No information.

Metabolism and Temperature Regulation

No information.

Drinking, Pellet-Casting, and Defecation

No information.

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