Department of Biology, University of Utah, 257 South 1400 East, Salt Lake City, UT 84112, USA.
Mol Ecol. 2009 Mar;18(5):782-91. doi: 10.1111/j.1365-294X.2008.04069.x.
Ocean warming will undoubtedly affect the migratory patterns of many marine species, but specific changes can be predicted only where behavioural mechanisms guiding migration are understood. Southern right whales show maternally inherited site fidelity to near-shore winter nursery grounds, but exactly where they feed in summer (collectively and individually) remains mysterious. They consume huge quantities of copepods and krill, and their reproductive rates respond to fluctuations in krill abundance linked to El Niño Southern Oscillation (ENSO). Here we show that genetic and isotopic signatures, analysed together, indicate maternally directed site fidelity to diverse summer feeding grounds for female right whales calving at Península Valdés, Argentina. Isotopic values from 131 skin samples span a broad range (-23.1 to -17.2‰ δ¹³C, 6.0 to 13.8‰ δ¹⁵N) and are more similar than expected among individuals sharing the same mitochondrial haplotype. This pattern indicates that calves learn summer feeding locations from their mothers, and that the timescale of culturally inherited site fidelity to feeding grounds is at least several generations. Such conservatism would be expected to limit the exploration of new feeding opportunities, and may explain why this population shows increased rates of reproductive failure in years following elevated sea-surface temperature anomalies off South Georgia, the richest known feeding ground for baleen whales in the South Atlantic.
海洋变暖无疑将影响许多海洋物种的迁徙模式，但只有在了解指导迁徙的行为机制的情况下，才能预测具体的变化。南方露脊鲸对近岸冬季育雏场表现出母系遗传的栖息地忠诚，但它们在夏季（集体和个体）的确切觅食地点仍然是个谜。它们消耗大量的桡足类和磷虾，它们的繁殖率对与厄尔尼诺南方涛动（ENSO）相关的磷虾丰度波动做出反应。在这里，我们表明，遗传和同位素特征的综合分析表明，在阿根廷瓦尔迪兹半岛产仔的雌性南方露脊鲸存在对不同夏季觅食地的母系指导的栖息地忠诚。131 个皮肤样本的同位素值跨度很广（-23.1 至-17.2‰δ¹³C，6.0 至 13.8‰δ¹⁵N），并且具有相同线粒体单倍型的个体之间的相似性超过预期。这种模式表明，幼鲸从母亲那里学习夏季觅食地点，并且对觅食地的文化遗传栖息地忠诚度的时间尺度至少为数代。这种保守性预计会限制对新觅食机会的探索，并且可以解释为什么在南乔治亚海域海表温度异常升高后的几年里，这个种群的繁殖失败率增加，南乔治亚是南大西洋已知的须鲸最丰富的觅食地。
