Marine Biology

, Volume 155, Issue 4, pp 443–450 | Cite as

Trophic segregation between sexes in the Black Skimmer revealed through the analysis of stable isotopes

  • Rocío Mariano-JelicichEmail author
  • Florencia Botto
  • Paulina Martinetto
  • Oscar Iribarne
  • Marco Favero
Original Paper


The degree of individual or gender variation when exploiting food resources is an important aspect in the study of foraging ecology within a population. Previous information on non-breeding skimmers obtained through conventional methodologies suggested sex-related differences in prey species. In this study, stable isotope techniques were used to investigate the intraspecific segregation in diet and foraging habits of the Black Skimmer (Rynchops niger intercedens) at Mar Chiquita Coastal Lagoon (37°40′S, 57°22′W), Argentina. These results were compared with contemporary data on the trophic composition obtained by conventional methodologies. Blood samples were taken from birds captured with mist-nets during their non-breeding season. The isotopic signatures of skimmers showed a diet mainly composed of marine prey with some degree of estuarine fish intake. When comparing diet between sexes, males showed enrichment in 15N compared to females, while no differences were observed in 13C. The use of mixing models revealed differences in the relative composition of prey in the diet of male and female skimmers. This study highlights stable isotope analysis as a valuable tool to test inter-individual differences and sexual segregation in trophic ecology of Black Skimmers as compared to conventional methodologies. The results show a trophic segregation in the Black Skimmer during the non-breeding season that can be explained by differences in prey species and larger prey sizes of male skimmers. Our findings have significant implications for conservation since any environmental change occurring at wintering areas might have profound effects on several avian life-history traits, and could be different for males and females due to trophic segregation.


Stable Isotope Large Prey Sexual Segregation Stable Isotope Signature Conventional Methodology 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We thank Mirta García, Flavio Quintana and Juan M. Díaz de Astarloa for providing helpful comments on an early version of the manuscript and C. García-Mata, P. Silva Rodríguez, G. García, A. Gómez Laich, G. Scioscia, J. P. Seco Pon, L. Josens, L. Mauco and M. S. Bó for their help in data gathering and logistic support. We thank three anonymous reviewers for their comments on earlier drafts of the manuscript. All the samplings were performed under permission and comply with the current laws of Buenos Aires Province, Argentina. Financial support was provided by the Universidad Nacional de Mar del Plata (Grant 15/E238), CONICET (Rs1294 and PIP5669), Fundación Antorchas (13900-13) and ANPCyT (1-7213). RMJ and PM were supported by fellowships from CONICET. This is part of RMJ’s Doctoral Dissertation.


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Rocío Mariano-Jelicich
    • 1
    • 3
    Email author
  • Florencia Botto
    • 2
    • 3
  • Paulina Martinetto
    • 2
    • 3
  • Oscar Iribarne
    • 2
    • 3
  • Marco Favero
    • 1
    • 3
  1. 1.Laboratorio de Vertebrados, Departamento de Biología, Facultad de Ciencias Exactas y NaturalesUniversidad Nacional de Mar del PlataMar del PlataArgentina
  2. 2.Laboratorio de Ecología, Departamento de Biología, Facultad de Ciencias Exactas y NaturalesUniversidad Nacional de Mar del PlataMar del PlataArgentina
  3. 3.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Ciudad Autónoma de Buenos AiresArgentina

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