Systematics

The Pink-footed Shearwater is closely related to Flesh-footed Shearwater (Ardenna carneipes) and Great Shearwater (Ardenna gravis) (18 Austin, J. J. (1996). Molecular phylogenetics of Puffinus shearwaters: preliminary evidence from mitochondrial cytochrome b gene sequences. Molecular Phylogenetics and Evolution 6(1):77–88. Close , 19 Penhallurick, J., and M. Wink (2004). Analysis of the taxonomy and nomenclature of the Procellariiformes based on complete nucleotide sequences of the mitochondrial cytochrome b gene. Emu 104(2):125–147. Close ). The authors of that study recommended that Ardenna creatopus be considered conspecific with Ardenna carneipes (19 Penhallurick, J., and M. Wink (2004). Analysis of the taxonomy and nomenclature of the Procellariiformes based on complete nucleotide sequences of the mitochondrial cytochrome b gene. Emu 104(2):125–147. Close ), but the two are still maintained as separate species by most authorities (e.g.,20 Dickinson, E. C., and J. V. Remsen, Editors (2013). The Howard and Moore Complete Checklist of the Birds of the World. Fourth edition. Volume 1. Aves Press, Eastbourne, UK. Close , 21 Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, J. A. Gerbracht, D. Lepage, B. L. Sullivan, and C. L. Wood (2021). The eBird/Clements Checklist of Birds of the World: v2021. Close ). Pink-footed Shearwater and other closely related species were split from the genus Puffinus and placed in Ardenna by the North American Classification Committee in 2016 (22 Chesser, R. T., K. J. Burns, C. Cicero, J. L. Dunn, A. W. Kratter, I. J. Lovette, P. C. Rasmussen, J. V. Remsen Jr., J. D. Rising, D. F. Stotz, and K. Winker (2016). Fifty-seventh supplement to the American Ornithologists' Union Check-list of North American Birds. Auk 133(3):544–560. Close ).

Breeding birds from the Juan Fernández Islands are larger and heavier than those from Isla Mocha, with proportionally stouter bills, thicker legs, and shorter tails (1 Guicking, D., W. Fiedler, C. Leuther, R. Schlatter, and P. H. Becker (2004). Morphometrics of the pink-footed shearwater (Puffinus creatopus): influence of sex and breeding site. Journal of Ornithology 145(1):64–68. Close ; see Appearance: Measurements). However, a genetic comparison of birds from those two populations found that they were relatively homogeneous, with little genetic structure (23 Segovia, D. (2012). Estimaciones de variabilidad genetica intra e interpoblacional en Puffinus creatopus. M.S. thesis. Universidad de Concepción, Concepción, Chile. Close ).

Monotypic.

Based on genetic evidence, the species is most closely related to Flesh-footed Shearwater. Both Pink-footed Shearwater and Flesh-footed Shearwater are also closely related to the Great Shearwater; it has been proposed that these three species have a “super-species relationship” (19 Penhallurick, J., and M. Wink (2004). Analysis of the taxonomy and nomenclature of the Procellariiformes based on complete nucleotide sequences of the mitochondrial cytochrome b gene. Emu 104(2):125–147. Close ). Other related species in the Ardenna clade of large shearwaters include Sooty Shearwater (Ardenna grisea), Short-tailed Shearwater (Ardenna tenuirostris), Buller's Shearwater (Ardenna bulleri), and Wedge-tailed Shearwater (Ardenna pacifica).

Little or no fossil evidence. A fragment tarsometatarsus from central Chile, dating to the Pliocene, had similarities to this species but was larger (24 Chávez Hoffmeister, M., J. D. Carrillo Briceño, and S. N. Nielsen (2014). The evolution of seabirds in the Humboldt Current: New clues from the Pliocene of central Chile. PLOS ONE 9(3):e90043. Close ). That fossil record was fragmentary and overlapped in size and morphology with several extant species, so it was not assigned to species (24 Chávez Hoffmeister, M., J. D. Carrillo Briceño, and S. N. Nielsen (2014). The evolution of seabirds in the Humboldt Current: New clues from the Pliocene of central Chile. PLOS ONE 9(3):e90043. Close ).