Volume 47, No. 1

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Using referential values of δ13C and δ15N to infer the foraging ecology of Galápagos seabirds


1Charles Darwin Research Station, Puerto Ayora, Galápagos, Ecuador
2Universidad San Francisco de Quito and Galápagos Science Center, Islas Galápagos, Ecuador *(
3Dirección del Parque Nacional Galápagos, Islas Galápagos, Ecuador


JIMÉNEZ-UZCÁTEGUI, G., VACA, L., COTÍN, J., GARCÍA, C., COSTALES, A., SEVILLA, C., & PÁEZ-ROSAS, D. 2019. Using referential values of δ13C and δ15N to infer the foraging ecology of Galápagos seabirds. Marine Ornithology 47: 5 - 10

Received 02 June 2018, accepted 23 August 2018

Date Published: 2019/04/15
Date Online: 2018/10/31
Key words: marine birds, Islas Galápagos, isotopic values, foraging strategies, trophic level


The Galápagos Penguin Spheniscus mendiculus, Flightless Cormorant Phalacrocorax harrisi, and Waved Albatross Phoebastria irrorata are endemic to Islas Galápagos. They are known to feed on different prey (including crustaceans, cephalopods, and/or several species of epipelagic and benthic fish), in accordance with different foraging strategies. In this work, we used stable-isotope analysis of carbon and nitrogen to corroborate available information on habitat use (δ13C) and trophic position (δ15N). Feather samples from the three species were collected in six different areas prior to the 2011 and 2012 breeding seasons. Results showed differences in foraging strategies between Galápagos Penguins and the other two species (δ13C and δ15N, P < 0.01). The Flightless Cormorant and Waved Albatross showed similar proportions of δ13C (P = 0.07), but they occupied different trophic levels (δ15N, P < 0.01). 


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