Fromant Aymeric, Schumann Nicole, Dann Peter, Cherel Yves, Arnould John P Y
School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia.
Centre d'Edutes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-La Rochelle Université, Villiers-en-bois, France.
PeerJ. 2020 Mar 11;8:e8700. doi: 10.7717/peerj.8700. eCollection 2020.
The foraging niches of seabirds are driven by a variety of factors, including competition for prey that promotes divergence in trophic niches. Bass Strait, south-eastern Australia, is a key region for seabirds, with little penguins , short-tailed shearwaters , fairy prions and common diving-petrels being particularly abundant in the region. The trophic niches of these species were investigated using isotopic values in whole blood and by identifying prey remains in stomach contents. The four species occupied different isotopic niches that varied among years, seasons and regions. Little penguins consumed mainly fish whereas the three procellariforms primarily consumed coastal krill . The dietary similarities between the procellariforms suggest that food resources are segregated in other ways, with interspecific differences in isotope niches possibly reflecting differential consumption of key prey, divergent foraging locations and depth, and differences in breeding phenology. Because oceanographic changes predicted to occur due to climate change may result in reduced coastal krill availability, adversely affecting these seabird predators, further information on foraging zones and feeding behaviour of small procellariform species is needed to elucidate more fully the segregation of foraging niches, the capacity of seabirds to adapt to climate change and the potential for interspecific competition in the region.
海鸟的觅食生态位受多种因素驱动，包括对猎物的竞争，这种竞争促使营养生态位产生分化。澳大利亚东南部的巴斯海峡是海鸟的关键区域，小企鹅、短尾鹱、仙锯鹱和普通潜海燕在该地区尤为丰富。利用全血中的同位素值并通过识别胃内容物中的猎物残骸，对这些物种的营养生态位进行了研究。这四个物种占据了不同的同位素生态位，这些生态位在年份、季节和区域之间存在差异。小企鹅主要以鱼类为食，而三种鹱形目鸟类主要以沿海磷虾为食。鹱形目鸟类之间的饮食相似性表明，食物资源以其他方式被分隔，同位素生态位的种间差异可能反映了关键猎物的不同消耗、觅食地点和深度的差异以及繁殖物候的差异。由于气候变化预计会导致海洋环境变化，可能会使沿海磷虾的可获得性降低，从而对这些海鸟捕食者产生不利影响，因此需要更多关于小型鹱形目物种觅食区和摄食行为的信息，以更全面地阐明觅食生态位的分隔、海鸟适应气候变化的能力以及该地区种间竞争的可能性。
