Carbon and nitrogen isotope fractionation of amino acids in an avian marine predator, the gentoo penguin (Pygoscelis papua)
Date
2015-02-25Author
McMahon, Kelton W.
Concept link
Polito, Michael J.
Concept link
Abel, Stephanie
Concept link
McCarthy, Matthew D.
Concept link
Thorrold, Simon R.
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/7215As published
https://doi.org/10.1002/ece3.1437DOI
10.1002/ece3.1437Keyword
Amino acid; Avian; Compound-specific stable isotope analysis; Diet; Fractionation; Penguin; Trophic positionAbstract
Compound-specific stable isotope analysis (CSIA) of amino acids (AA) has rapidly become a powerful tool in studies of food web architecture, resource use, and biogeochemical cycling. However, applications to avian ecology have been limited because no controlled studies have examined the patterns in AA isotope fractionation in birds. We conducted a controlled CSIA feeding experiment on an avian species, the gentoo penguin (Pygoscelis papua), to examine patterns in individual AA carbon and nitrogen stable isotope fractionation between diet (D) and consumer (C) (Δ13CC-D and Δ15NC-D, respectively). We found that essential AA δ13C values and source AA δ15N values in feathers showed minimal trophic fractionation between diet and consumer, providing independent but complimentary archival proxies for primary producers and nitrogen sources respectively, at the base of food webs supporting penguins. Variations in nonessential AA Δ13CC-D values reflected differences in macromolecule sources used for biosynthesis (e.g., protein vs. lipids) and provided a metric to assess resource utilization. The avian-specific nitrogen trophic discrimination factor (TDFGlu-Phe = 3.5 ± 0.4‰) that we calculated from the difference in trophic fractionation (Δ15NC-D) of glutamic acid and phenylalanine was significantly lower than the conventional literature value of 7.6‰. Trophic positions of five species of wild penguins calculated using a multi-TDFGlu-Phe equation with the avian-specific TDFGlu-Phe value from our experiment provided estimates that were more ecologically realistic than estimates using a single TDFGlu-Phe of 7.6‰ from the previous literature. Our results provide a quantitative, mechanistic framework for the use of CSIA in nonlethal, archival feathers to study the movement and foraging ecology of avian consumers.
Description
© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecology and Evolution 5 (2015): 1278–1290, doi:10.1002/ece3.1437.
Collections
Suggested Citation
Ecology and Evolution 5 (2015): 1278–1290The following license files are associated with this item:
Related items
Showing items related by title, author, creator and subject.
-
Stable isotope analyses of feather amino acids identify penguin migration strategies at ocean basin scales
Polito, Michael J.; Hinke, Jefferson T.; Hart, Tom; Santos, Mercedes; Houghton, Leah A.; Thorrold, Simon R. (2017-07)Identifying the at-sea distribution of wide ranging 20 marine predators is critical to understanding their ecology. Advances in electronic tracking devices and intrinsic biogeochemical markers have greatly improved our ... -
Amino acid isotopes from mussels along the California margin from 2009-2013 (Amino Acid Sediment 15N project)
McCarthy, Matthew D. (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-06-11)Amino acid isotopes from mussels along the California margin from 2009-2013 (Amino Acid Sediment 15N project) For a complete list of measurements, refer to the full dataset description in the supplemental file ... -
Mean d15N of individual amino acids and bulk organic matter for five plankton size fractions
McCarthy, Matthew D. (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-19)Mean d15N of individual amino acids and bulk organic matter for five plankton size fractions from R/V Sarmiento de Gamboa Malaspina_2011 in the Subtropical North Atlantic Ocean from January to March 2011 For a complete ...