INVESTIGADORES
BOTTO Florencia
artículos
Título:
Trophic segregation between sexes in the Black Skimmer revealed through the analysis of stable isotopes
Autor/es:
ROCIO MARIANO-JELICICH; FLORENCIA BOTTO; PAULINA MARTINETTO; OSCAR IRIBARNE; MARCO FAVERO
Revista:
MARINE BIOLOGY
Editorial:
SPRINGER
Referencias:
Año: 2008 p. 443 - 450
ISSN:
0025-3162
Resumen:
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_400S, 57_220W), 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.