Southern Giant Petrel counts and Magellanic Penguin fledging weights ...

• Main Authors: Wagner, Eric, Rebstock, Ginger, Boersma, P. Dee
• Format: Dataset
• Language: English
• Published: Dryad 2024
• Subjects: FOS Natural sciences; Southern giant petrel; Macronectes giganteus; Magellanic penguin; Predation; Peak Fledging; Spheniscus Magellanicus; Argentina; Giganteus; Giant Petrel; Giant Petrels
• Online Access: https://dx.doi.org/10.5061/dryad.zkh1893ht; https://datadryad.org/stash/dataset/doi:10.5061/dryad.zkh1893ht

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. ... : # Southern Giant Petrel counts and Magellanic Penguin fledging weights [https://doi.org/10.5061/dryad.zkh1893ht](https://doi.org/10.5061/dryad.zkh1893ht) This repository contains two datasets from a study of Southern Giant Petrel predation of Magellanic Penguins. The first dataset contains counts of giant petrels attending a beach at the Magellanic Penguin colony at Punta Tombo, Argentina, from 1986 to 2023 to determine seasonal phenology. The second dataset contains the departure weights of Magellanic Penguin chicks from when they fledged between 2007 and 2023, to determine temporal trends. ## Description of the data and file structure Included are two .csv files. The Southern Giant Petrel count dataset has 1,726 counts with the count of giant petrels, the year in which it was done (called BookYear in our scheme), the Days Since September 1, and whether the count was done in the AM or PM (the Time column). The fledgling weight dataset has ~1,060 observations with year (as BookYear again), Julian Day, Days ...