Cognitive and Behavioural Ecology Program, Memorial University of Newfoundland, St John's, NL, Canada, A1B 3X9
Department of Biochemistry, Memorial University of Newfoundland, St John's, NL, Canada, A1B 3X9.
J Exp Biol. 2021 Feb 24;224(Pt 4):jeb235929. doi: 10.1242/jeb.235929.
Consuming omega-3 fatty acids (n-3 LCPUFAs) during development improves cognition in mammals, but the effect remains untested in other taxa. In aquatic ecosystems, n-3 LCPUFAs are produced by phytoplankton and bioaccumulate in the food web. Alarmingly, the warming and acidification of aquatic systems caused by climate change impair n-3 LCPUFA production, with an anticipated decrease of 80% by the year 2100. We tested whether n-3 LCPUFA consumption affects the physiology, morphology, behaviour and cognition of the chicks of a top marine predator, the ring-billed gull. Using a colony with little access to n-3 LCPUFAs, we supplemented siblings from 22 fenced nests with contrasting treatments from hatching until fledging; one sibling received n-3 LCPUFA-rich fish oil and the other, a control sucrose solution without n-3 LCPUFAs. Halfway through the nestling period, half the chicks receiving fish oil were switched to the sucrose solution to test whether n-3 LCPUFA intake remains crucial past the main growth phase (chronic versus transient treatments). Upon fledging, n-3 LCPUFAs were elevated in the blood and brains of chicks receiving the chronic treatment, but were comparable to control levels among those receiving the transient treatment. Across the entire sample, chicks with elevated n-3 LCPUFAs in their tissues fledged earlier despite their morphology and activity levels being unrelated to fledging age. Fledging required chicks to escape fences encircling their nest. We therefore interpret fledging age as a possible indicator of cognition, with chicks with improved cognition fledging earlier. These results provide insight into whether declining dietary n-3 LCPUFAs will compromise top predators' problem-solving skills, and thus their ability to survive in a rapidly changing world.
在发育过程中摄入欧米伽-3 脂肪酸（n-3 LCPUFAs）可以改善哺乳动物的认知能力，但这一效应在其他分类群中尚未得到验证。在水生生态系统中，n-3 LCPUFAs 由浮游植物产生，并在食物链中生物积累。令人担忧的是，气候变化导致的水生系统变暖酸化会损害 n-3 LCPUFA 的产生，预计到 2100 年，其产生量将减少 80%。我们测试了 n-3 LCPUFA 的摄入是否会影响顶级海洋捕食者环嘴鸥幼鸟的生理、形态、行为和认知。我们利用一个很少接触 n-3 LCPUFAs 的环嘴鸥繁殖地，从孵化到离巢为止，用富含 n-3 LCPUFA 的鱼油和不含 n-3 LCPUFA 的蔗糖溶液对来自 22 个围栏鸟巢的兄弟姐妹进行了对比处理；一半接受鱼油的幼鸟在育雏中期被换成蔗糖溶液，以测试 n-3 LCPUFA 的摄入是否在主要生长阶段之后仍然至关重要（慢性与短暂处理）。离巢时，接受慢性处理的幼鸟血液和大脑中的 n-3 LCPUFAs 水平升高，但接受短暂处理的幼鸟水平与对照组相当。在整个样本中，尽管形态和活动水平与离巢年龄无关，但组织中 n-3 LCPUFAs 升高的幼鸟更早离巢。离巢需要幼鸟逃离环绕其巢的围栏。因此，我们将离巢年龄解释为认知能力的一个可能指标，认知能力提高的幼鸟更早离巢。这些结果提供了关于饮食中 n-3 LCPUFAs 减少是否会损害顶级捕食者解决问题的能力，以及它们在快速变化的世界中生存的能力的见解。
