Regional Differences in the Diets of Adélie and Emperor Penguins in the Ross Sea, Antarctica

• Published in: Animals
• Main Authors: Seo-Yeon Hong, Jong-Ku Gal, Bo-Yeon Lee, Wu-Ju Son, Jin-Woo Jung, Hyung-Sul La, Kyung-Hoon Shin, Jeong-Hoon Kim, Sun-Yong Ha
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2021
• Subjects: stable isotope analysis; Adélie Penguin; Emperor Penguin; Ross Sea; SIAR; Antarctic; Cape Hallett; Cape Washington; Coulman Island; Hallett; Inexpressible Island; Terra Nova Bay; Antarc*; Antarctic Krill; Antarctic silverfish; Antarctica; Aptenodytes forsteri; Emperor penguins; Euphausia superba; Pygoscelis adeliae
• Online Access: https://doi.org/10.3390/ani11092681

To identify the dietary composition and characteristics of both Adélie (Pygoscelis adeliae) and Emperor (Aptenodytes forsteri) penguins at four breeding sites, we performed stable carbon (δ13C) and nitrogen (δ15N) isotope analysis of down samples taken from penguin chicks. Adélie Penguin chicks at Cape Hallett mostly fed on Antarctic krill (Euphausia superba; 65.5 ± 3.5%), a reflection of the prevalence of that species near Cape Hallett, and no significant differences were noted between 2017 and 2018. However, Adélie Penguin chicks at Inexpressible Island, located near Terra Nova Bay, fed on both Antarctic silverfish (Pleuragramma antarctica; 42.5%) and ice krill (Euphausia crystallorophias; 47%), reflecting the high biomass observed in Terra Nova Bay. Meanwhile, no significant difference was noted between the two breeding sites of the Emperor Penguin. Emperor Penguin chicks predominantly fed on Antarctic silverfish (74.5 ± 2.1%) at both breeding sites (Cape Washington and Coulman Island), suggesting that diet preference represents the main factor influencing Emperor Penguin foraging. In contrast, the diet of the Adélie Penguin reflects presumed regional differences in prey prevalence, as inferred from available survey data.