A fearful scourge to the penguin colonies: Southern giant petrel ( Macronectes giganteus) predation on living Magellanic penguins ( Spheniscus magellanicus) may be more common than assumed

Abstract Southern giant petrels ( Macronectes giganteus ) are important consumers that range across the oceans throughout the southern hemisphere. In Argentina, previous studies have shown they eat primarily pinnipeds and penguins, which they are assumed to scavenge, although there are occasional an...

Full description

Bibliographic Details
Published in:Ecology and Evolution
Main Authors: Wagner, Eric L., Rebstock, Ginger A., Boersma, P. Dee
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2024
Subjects:
Online Access:http://dx.doi.org/10.1002/ece3.11258
https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.11258
Description
Summary:Abstract Southern giant petrels ( Macronectes giganteus ) are important consumers that range across the oceans throughout the southern hemisphere. In Argentina, previous studies have shown they eat primarily pinnipeds and penguins, which they are assumed to scavenge, although there are occasional anecdotes of them attacking living penguins. Here we describe a predation attempt by a trio of southern giant petrels on a molting adult Magellanic penguin ( Spheniscus magellanicus ) at the large colony at Punta Tombo, Argentina. We relate giant petrel attendance patterns at the colony to the penguins' phenology, showing how giant petrel numbers rise with the increasing prevalence of vulnerable penguins. We suggest that living penguins—both fledglings and adults—may constitute a more seasonally significant proportion of the giant petrel diet than previously assumed, and their capture may represent a specialized predation technique.