Marine top predators living in sympatry tend to use their environment differentially, thereby reducing niche overlap. Magellanic penguins (Spheniscus magellanicus) and gentoo penguins (Pygoscelis papua) coexist at Martillo Is., Argentina. During the 2014, 2015 and 2017 breeding seasons a total of thirty-one Magellanic and eleven gentoo penguins were equipped with GPS-TDR loggers to record foraging trips. Both species dove to similar maximum depths with analogous effort (dives per hour). Magellanics, however, undertook longer trips and travelled further away from the colony (25 h and 43 km vs. 10 h and 20 km on average, respectively). Gentoos on the other hand, performed longer dives, had a higher percentage of “U” shaped dives and spent more time during the bottom phase of the dive. Gentoos foraged exclusively within an area close to the colony and in waters not deeper than 80 m. Magellanics had more variability in their behaviors and were not associated to a specific depth or distance from the colony. The ecological circumstances of both species (targeted prey and surrounding environment) suffice to explain the particular behaviors of both species independently from the presence of the other. Gentoos seem to focus on benthic prey which remains stable in this environment throughout the year, and Magellanics behave more opportunistically searching for pelagic prey during early chick rearing. Competition may not be always shaping coexistence of species of similar trophic positions and behaviors. Particularly, if resources are not limited, both species can behave in ways they find optimal without factoring the coexistence of the other species.

中文翻译：

---

阿根廷 Martillo 岛共存的 gentoo Pygoscelis papua 和 Magellanic 企鹅 Spheniscus magellanicus 之间的生态位划分

生活在同种环境中的海洋顶级捕食者倾向于差异化地利用它们的环境，从而减少生态位重叠。麦哲伦企鹅 (Spheniscus magellanicus) 和巴布亚巴布亚巴布亚巴布亚巴布亚企鹅 (Pygoscelis papua) 共存于阿根廷马蒂略岛。在 2014 年、2015 年和 2017 年的繁殖季节，共有 31 只麦哲伦企鹅和 11 只巴布亚企鹅配备了 GPS-TDR 记录器来记录觅食行程。两个物种都以类似的努力（每小时潜水）潜入相似的最大深度。然而，麦哲伦进行了更长的旅行并且远离了殖民地（分别为 25 小时和 43 公里，而平均分别为 10 小时和 20 公里）。另一方面，Gentoos 的潜水时间更长，“U”形潜水的比例更高，并且在潜水的底部阶段花费的时间更长。Gentoos 仅在靠近殖民地的区域内和不超过 80 m 的水域中觅食。Magellanics 的行为有更多的可变性，并且与特定的深度或距殖民地的距离无关。两个物种的生态环境（目标猎物和周围环境）足以独立于另一个物种的存在来解释两个物种的特定行为。Gentoos 似乎专注于全年在这种环境中保持稳定的底栖猎物，而 Magellanics 在早期雏鸡饲养期间表现得更加机会主义地寻找远洋猎物。竞争可能并不总是塑造具有相似营养位置和行为的物种的共存。特别是，如果资源不受限制，