The ecological drivers underlying breeding performance are expected to differ across the geographical range of seabird species, but few studies have compared trade-offs between colonies with different local conditions. During chick-rearing (2000–01), we compared the foraging trips, diet and breeding parameters of two Adélie penguin colonies in the Ross Sea, at Edmonson Point (EdPo; ~2000 breeding pairs) and Inexpressible Island (InIs; ~24 000 breeding pairs). Penguins from InIs travelled farther and performed longer feeding trips. The quantity of food brought to the nest was the same for the two colonies, but penguins from InIs brought more fish and less krill. Eggs hatched earlier at EdPo. Breeding success did not differ, but chick weight during hatching–fledging was greater at InIs. Despite worse weather conditions at InIs, the larger proportion of high-energy food brought by penguins from InIs (i.e. fish) may explain their offspring‘s better performance. In addition, the persistence of fast ice at EdPo may have led to greater energy expenditure of breeding individuals, possibly reducing chick growth. The greater intraspecific competition expected at InIs may have been reduced by longer foraging trips and/or counteracted by the more nutritious diet. Our findings reveal complex trade-offs between foraging effort and environmental constraints in determining the breeding performance of Adélie penguins.

中文翻译：

---

去钓鱼：阿德利企鹅特定地点的觅食策略和繁殖性能

预计繁殖性能的生态驱动因素在海鸟物种的地理范围内会有所不同，但很少有研究比较不同当地条件的殖民地之间的权衡。在小鸡饲养期间（2000-01 年），我们比较了埃德蒙森角（EdPo；~2000 对繁殖对）和不可表达岛（InIs；~24 000繁殖对）。来自 InIs 的企鹅走得更远，并且进行了更长的觅食行程。两个殖民地带回巢穴的食物数量相同，但来自 InIs 的企鹅带来了更多的鱼和更少的磷虾。鸡蛋在 EdPo 孵化得更早。育种成功率没有差异，但在 InIs 孵化期间的雏鸡重量更大。尽管 InIs 的天气条件更糟，来自InIs（即鱼）的企鹅带来的高能量食物比例较大，这可能解释了它们的后代更好的表现。此外，EdPo 中快速冰的持续存在可能导致繁殖个体的能量消耗增加，可能会降低雏鸡的生长。更长的觅食行程和/或更有营养的饮食可能抵消了 InIs 预期的更大的种内竞争。我们的研究结果揭示了在确定阿德利企鹅的繁殖性能时，觅食努力和环境限制之间的复杂权衡。更长的觅食行程和/或更有营养的饮食可能抵消了 InIs 预期的更大的种内竞争。我们的研究结果揭示了在确定阿德利企鹅的繁殖性能时，觅食努力和环境限制之间的复杂权衡。更长的觅食行程和/或更有营养的饮食可能抵消了 InIs 预期的更大的种内竞争。我们的研究结果揭示了在确定阿德利企鹅的繁殖性能时，觅食努力和环境限制之间的复杂权衡。