Document Detail

Isotopic segregation between sympatric seabird species increases with nutritional stress.
MedLine Citation:
PMID:  22171022     Owner:  NLM     Status:  MEDLINE    
Dietary segregation is essential for the coexistence of closely related species of animals. However, little is known about how changes in availability of food resources might affect trophic interactions of wild animals breeding in sympatry. Here, we examined how interannual variations in relative food availability (as reflected in blood levels of stress hormone corticosterone, CORT) affect food partitioning (assessed via a comparison of stable isotope δ(15)N and δ(13)C ratios of blood) between the common murre (Uria aalge) and thick-billed murre (Uria lomvia), breeding on a single colony in the Bering Sea. During a 6-year study, CORT varied among years but not between species, whereas stable isotope ratios varied among years and between species. Isotopic distance between species increased with increasing CORT. These results indicate that, when food was not limiting, both species relied on similar food resources. As foraging conditions deteriorated, murres diverged in their diets. We conclude that the degree of dietary segregation between Uria spp. varies with changes in the availability of food and is greatest during food shortages.
Christopher P Barger; Alexander S Kitaysky
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2011-12-14
Journal Detail:
Title:  Biology letters     Volume:  8     ISSN:  1744-957X     ISO Abbreviation:  Biol. Lett.     Publication Date:  2012 Jun 
Date Detail:
Created Date:  2012-05-14     Completed Date:  2012-09-11     Revised Date:  2013-06-27    
Medline Journal Info:
Nlm Unique ID:  101247722     Medline TA:  Biol Lett     Country:  England    
Other Details:
Languages:  eng     Pagination:  442-5     Citation Subset:  IM    
Department of Biology and Wildlife, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
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MeSH Terms
Carbon / blood*
Carbon Isotopes / blood
Charadriiformes / physiology*
Competitive Behavior
Corticosterone / blood*
Food Preferences*
Nitrogen / blood*
Nitrogen Isotopes / blood
Species Specificity
Stress, Physiological
Reg. No./Substance:
0/Carbon Isotopes; 0/Nitrogen Isotopes; 50-22-6/Corticosterone; 7440-44-0/Carbon; 7727-37-9/Nitrogen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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