Isotopic Discrimination between Food and Blood and Feathers of Captive Penguins: Implications for Dietary Studies in the Wild
International audience Using measurements of naturally occurring stable isotopes to reconstruct diets or source of feeding requires quantifying isotopic discrimination factors or the relationships between isotope ratios in food and in consumer tissues. Diet-tissue discrimination factors of carbon (1...
Main Authors: | , , |
---|---|
Other Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2005
|
Subjects: | |
Online Access: | https://hal.science/hal-00187664 |
id |
ftunivnantes:oai:HAL:hal-00187664v1 |
---|---|
record_format |
openpolar |
spelling |
ftunivnantes:oai:HAL:hal-00187664v1 2023-05-15T18:03:52+02:00 Isotopic Discrimination between Food and Blood and Feathers of Captive Penguins: Implications for Dietary Studies in the Wild Cherel, Yves Hobson, Keith A. Hassani, Sami Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Environment and Climate Change Canada Océanopolis Brest 2005 https://hal.science/hal-00187664 en eng HAL CCSD University of Chicago Press hal-00187664 https://hal.science/hal-00187664 ISSN: 1522-2152 EISSN: 1537-5293 Physiological and Biochemical Zoology https://hal.science/hal-00187664 Physiological and Biochemical Zoology, 2005, 78 (1), pp.106-115 [SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.ES]Environmental Sciences/Environmental and Society info:eu-repo/semantics/article Journal articles 2005 ftunivnantes 2023-02-08T08:22:16Z International audience Using measurements of naturally occurring stable isotopes to reconstruct diets or source of feeding requires quantifying isotopic discrimination factors or the relationships between isotope ratios in food and in consumer tissues. Diet-tissue discrimination factors of carbon (13C/12C, or d13C) and nitrogen (15N/14N, or d15N) isotopes in whole blood and feathers, representing noninvasive sampling techniques, were examined using three species of captive penguins (king Aptenodytes patagonicus, gentoo Pygoscelis papua, and rockhopper Eudyptes chrysocome penguins) fed known diets. King and rockhopper penguins raised on a constant diet of herring and capelin, respectively, had tissues enriched in 15N compared to fish, with discrimination factors being higher in feathers than in blood. These data, together with previous works, allowed us to calculate average discrimination factors for 15N between whole lipid-free prey and blood and feathers of piscivorous birds; they amount to 2.7‰ and 4.2‰, respectively. Both fish species were segregated by their d13C and d15N values, and importantly, lipid-free fish muscle tissue was consistently depleted in 13C and enriched in 15N compared to whole lipid-free fish. This finding has important implications because previous studies usually base dietary reconstructions on muscle of prey rather than on whole prey items consumed by the predator.We tested the effect of these differences using mass balance calculations to the quantification of food sources of gentoo penguins that had a mixed diet. Modeling indicated correct estimates when using the isotopic signature of whole fish (muscle) and the discrimination factors between whole fish (muscle) and penguin blood. Conversely, the use of isotopic signatures of muscle together with discrimination factors between whole fish and blood (or the reverse) leads to spurious estimates in food proportions. Consequently, great care must be taken in the choice of isotopic discrimination factors to apply to wild species for ... Article in Journal/Newspaper Pygoscelis papua Université de Nantes: HAL-UNIV-NANTES |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.ES]Environmental Sciences/Environmental and Society |
spellingShingle |
[SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.ES]Environmental Sciences/Environmental and Society Cherel, Yves Hobson, Keith A. Hassani, Sami Isotopic Discrimination between Food and Blood and Feathers of Captive Penguins: Implications for Dietary Studies in the Wild |
topic_facet |
[SDE.BE]Environmental Sciences/Biodiversity and Ecology [SDE.ES]Environmental Sciences/Environmental and Society |
description |
International audience Using measurements of naturally occurring stable isotopes to reconstruct diets or source of feeding requires quantifying isotopic discrimination factors or the relationships between isotope ratios in food and in consumer tissues. Diet-tissue discrimination factors of carbon (13C/12C, or d13C) and nitrogen (15N/14N, or d15N) isotopes in whole blood and feathers, representing noninvasive sampling techniques, were examined using three species of captive penguins (king Aptenodytes patagonicus, gentoo Pygoscelis papua, and rockhopper Eudyptes chrysocome penguins) fed known diets. King and rockhopper penguins raised on a constant diet of herring and capelin, respectively, had tissues enriched in 15N compared to fish, with discrimination factors being higher in feathers than in blood. These data, together with previous works, allowed us to calculate average discrimination factors for 15N between whole lipid-free prey and blood and feathers of piscivorous birds; they amount to 2.7‰ and 4.2‰, respectively. Both fish species were segregated by their d13C and d15N values, and importantly, lipid-free fish muscle tissue was consistently depleted in 13C and enriched in 15N compared to whole lipid-free fish. This finding has important implications because previous studies usually base dietary reconstructions on muscle of prey rather than on whole prey items consumed by the predator.We tested the effect of these differences using mass balance calculations to the quantification of food sources of gentoo penguins that had a mixed diet. Modeling indicated correct estimates when using the isotopic signature of whole fish (muscle) and the discrimination factors between whole fish (muscle) and penguin blood. Conversely, the use of isotopic signatures of muscle together with discrimination factors between whole fish and blood (or the reverse) leads to spurious estimates in food proportions. Consequently, great care must be taken in the choice of isotopic discrimination factors to apply to wild species for ... |
author2 |
Centre d'Études Biologiques de Chizé (CEBC) Centre National de la Recherche Scientifique (CNRS) Environment and Climate Change Canada Océanopolis Brest |
format |
Article in Journal/Newspaper |
author |
Cherel, Yves Hobson, Keith A. Hassani, Sami |
author_facet |
Cherel, Yves Hobson, Keith A. Hassani, Sami |
author_sort |
Cherel, Yves |
title |
Isotopic Discrimination between Food and Blood and Feathers of Captive Penguins: Implications for Dietary Studies in the Wild |
title_short |
Isotopic Discrimination between Food and Blood and Feathers of Captive Penguins: Implications for Dietary Studies in the Wild |
title_full |
Isotopic Discrimination between Food and Blood and Feathers of Captive Penguins: Implications for Dietary Studies in the Wild |
title_fullStr |
Isotopic Discrimination between Food and Blood and Feathers of Captive Penguins: Implications for Dietary Studies in the Wild |
title_full_unstemmed |
Isotopic Discrimination between Food and Blood and Feathers of Captive Penguins: Implications for Dietary Studies in the Wild |
title_sort |
isotopic discrimination between food and blood and feathers of captive penguins: implications for dietary studies in the wild |
publisher |
HAL CCSD |
publishDate |
2005 |
url |
https://hal.science/hal-00187664 |
genre |
Pygoscelis papua |
genre_facet |
Pygoscelis papua |
op_source |
ISSN: 1522-2152 EISSN: 1537-5293 Physiological and Biochemical Zoology https://hal.science/hal-00187664 Physiological and Biochemical Zoology, 2005, 78 (1), pp.106-115 |
op_relation |
hal-00187664 https://hal.science/hal-00187664 |
_version_ |
1766174883324100608 |