CSA - Programa Punta San Juan, Centro para la Sostenibilidad Ambiental, Universidad Peruana Cayetano Heredia, Av. Armendáriz 445, Miraflores, Lima, Peru.
MARE - Marine and Environmental Sciences Centre, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, 3000-456, Coimbra, Portugal.
Mar Environ Res. 2019 Sep;150:104755. doi: 10.1016/j.marenvres.2019.104755. Epub 2019 Jul 5.
The Humboldt Current System presents high interannual variability, influenced by the El Niño Southern Oscillation (ENSO), whose implications in wildlife are not fully understood. We studied the isotopic niche of wild Humboldt penguins at Punta San Juan (Peru) during the pre-moult foraging trip in 4 consecutive years (2008-2011) under known oceanographic (ENSO) conditions. Our results show that there is a clear isotopic niche segregation (on both δC and δN values) of wild Humboldt penguins among all years. Besides isotopic niche segregation, niche width also varied significantly among years. The larger isotopic niche displayed in 2008 reflected the opportunistic feeding behaviour of Humboldt penguins when oceanographic conditions were unfavourable (i.e. El Niño of strong intensity). In contrast, and despite strong segregation, penguins displayed a more specialist behaviour in years of mild environmental conditions (i.e. 2009 "warm-weak", 2010 "neutral" and 2011 "warm-moderate"). No evidence of sexual segregation in wild Humboldt penguins during the pre-moulting foraging trip was found. This study highlights the coping mechanisms of an endangered species to changes in environmental conditions (i.e. overall, from strong to neutral El Niño events), which should have important ramifications in the management of the marine ecosystem in Peru, particularly the one related to the anchovy industry.
洪堡海流系统具有高度的年际可变性，受厄尔尼诺南方涛动（ENSO）的影响，但其对野生动物的影响尚未完全了解。我们在已知海洋学（ENSO）条件下，连续 4 年（2008-2011 年）在蓬塔圣胡安市（秘鲁）进行换羽前觅食旅行期间，研究了野生洪堡企鹅的同位素生态位。我们的研究结果表明，在所有年份中，野生洪堡企鹅之间存在明显的同位素生态位分离（在δC 和δN 值上）。除了同位素生态位分离外，生态位宽度在各年均存在显著差异。2008 年显示出较大的同位素生态位，反映了洪堡企鹅在海洋条件不利时（即强厄尔尼诺现象）的机会主义觅食行为。相比之下，尽管存在明显的分离，但在环境条件较为温和的年份（即 2009 年“暖弱”、2010 年“中性”和 2011 年“暖中度”），企鹅表现出更为专业化的行为。在换羽前觅食旅行期间，没有发现野生洪堡企鹅的性别分离现象。本研究强调了一个濒危物种对环境条件变化的适应机制（即总体而言，从强厄尔尼诺事件到中性厄尔尼诺事件），这对秘鲁海洋生态系统的管理，特别是与凤尾鱼产业相关的管理，应具有重要影响。
