Dear MARMAM-readers,
We are pleased to inform you that our paper ‘Ontogenetic and gender-related variation in the isotopic niche within and between three species of fur seals (genus Arctocephalus) by T.L. Albernaz, E.R, Secchi, L.R. Oliveira & S. Botta is now available online at Hydrobiologia DOI 10.1007/s10750-016-2950-0 http://link.springer.com/article/10.1007/s10750-016- 2950-0?wt_mc=Internal.Event.1.SEM.ArticleAuthorOnlineFirst <http://jeb.biologists.org/content/early/2016/05/25/jeb.133116> Abstract: We used an isotopic approach to investigate the intra- and interspecific differences in spatial and trophic ecology of three species of the fur seal genus *Arctocephalus* that inhabit distinct climatic zones: subtropical (*A. australis *n=22), subantarctic (*A. tropicalis *n=8) and polar (*A. gazella *n=10). We obtained sequential *δ*13C and *δ*15N values in dentine from canine teeth of specimens found along the southern Brazilian coast. We calculated isotopic niches where axes where used as a surrogate for trophic (*δ*15N) and spatial (*δ*13C) dimensions of the ecological niche. Further, we adjusted generalized additive mixed models to chronological data of *δ*13C and *δ*15N to investigate the ontogenetic variation of the isotopic niche. The three species showed significant segregation both in spatial and the trophic dimensions as a result of foraging at different latitudes. Within *A. australis, *males occupied higher trophic positions than females. Furthermore, some isotopic niche overlap was found between sexes in *A. tropicalis* and *A. gazella,* though sample sizes preclude conclusive interpretation. Marked ontogenetic variation in the isotopic niche, especially in the early years, was observed in all species. Isotopic niche suggest that intra and interspecific competition in these otariids is minimized by different degree of spatial and trophic segregation. For any inquiries or requests please contact me at: silbo...@gmail.com Kind regards, Silvina Botta Labotatório de Ecologia e Conservação da Megafauna Marinha Instituto de Oceanografia Universidade Federal do Rio Grande - FURG Brasil
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