Intra- and interspecific niche partitioning in striped and common dolphins inhabiting the southwestern Mediterranean Sea

Marine ecology progress series

, Carolina Fernández-Maldonado¹  *, Ana Cañadas²  , Juan José Castillo³  Joan Giménez⁴  , Francisco Ramírez⁴  , Susana García-Tiscar⁵  , Isabel Afán⁶ 

[1] Agencia de Medio Ambiente y Agua de Andalucía, Consejería de Medio Ambiente y Ordenación del Territorio, Junta de Andalucía, Johann G. Gutenberg 1, Isla de la Cartuja, 41092 Seville, Spain;Alnilam Research and Conservation, Pradillos 29, 28491 Navacerrada, Madrid, Spain;Centro de Recuperación de Especies Marinas Amenazadas (CREMA), Aula del Mar de Málaga, Pacífico 80, 29004 Málaga, Spain;Department of Conservation Biology, Estación Biológica de Doñana - Consejo Superior de Investigaciones Científicas (EBD-CSIC), Américo Vespucio s/n, Isla de la Cartuja, 41092 Seville, Spain;Department of Ecology, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain;Laboratorio de SIG y Teledetección (LAST), Estación Biológica de Doñana - Consejo Superior de Investigaciones Científicas (EBD-CSIC), Americo Vespucio s/n, Isla de la Cartuja, 41092 Seville, Spain

关键词: Stable isotopes;    Spatial modelling;    Niche partitioning;    Co-occurring species;    Segregation;    Stenella coeruleoalba;    Delphinus delphis;   

DOI  :  10.3354/meps12046

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

Community structure and functioning is shaped by resource partitioning between co-occurring species. Niche differentiation among sympatric species can be reached through trophic, spatial or temporal segregation to avoid competitive exclusion. Intraspecific segregation in the use of habitats and resources might determine, in turn, a population’s niche width and interspecific segregation. The Alboran Sea is the only area in the Mediterranean where common and striped dolphins coexist abundantly. Therefore, these putative competing species provided the opportunity to investigate niche partitioning through spatial modelling and trophic analysis. Density surface modelling and nitrogen and carbon stable isotopes (δ¹⁵N and δ¹³C) were used to investigate spatial and trophic niche partitioning at inter- and intraspecific levels. The 2 species showed high isotopic overlap. However, we could not rule out the possibility of interspecific trophic segregation, as isotopic similarity does not necessarily mean true ecological or dietary similarity. Among conspecifics, variations in δ¹⁵N and δ¹³C values with dolphin length pointed to ontogenetic dietary changes in striped dolphins, while sex played only a minor role in δ¹³C values. Spatially, these species tended to segregate their core areas of distribution, with common dolphins being more coastal than striped dolphins, which occupied adjacent, deeper waters. Overall, the main enabler for the coexistence of common and striped dolphins in the Alboran Sea was spatial segregation.

【 授权许可】

Unknown