NOAA Southwest Fisheries Science Center, Environmental Research Division, 99 Pacific St. #255A, Monterey, CA, 93940, USA.
Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA.
Ecol Lett. 2018 Jan;21(1):63-71. doi: 10.1111/ele.12871. Epub 2017 Nov 2.
Individual behavioural specialisation has far-reaching effects on fitness and population persistence. Theory predicts that unconditional site fidelity, that is fidelity to a site independent of past outcome, provides a fitness advantage in unpredictable environments. However, the benefits of alternative site fidelity strategies driving intraspecific variation remain poorly understood and have not been evaluated in different environmental contexts. We show that contrary to expectation, strong and weak site fidelity strategies in migratory northern elephant seals performed similarly over 10 years, but the success of each strategy varied interannually and was strongly mediated by climate conditions. Strong fidelity facilitated stable energetic rewards and low risk, while weak fidelity facilitated high rewards and high risk. Weak fidelity outperformed strong fidelity in anomalous climate conditions, suggesting that the evolutionary benefits of site fidelity may be upended by increasing environmental variability. We highlight how individual behavioural specialisation may modulate the adaptive capacity of species to climate change.
个体行为特化对适合度和种群存续有深远影响。理论预测，无条件的地点忠诚度，即独立于过去结果的对一个地点的忠诚度，在不可预测的环境中提供了适合度优势。然而，驱动种内变异的替代地点忠诚度策略的好处仍知之甚少，并且尚未在不同的环境背景下进行评估。我们表明，与预期相反，在 10 多年的时间里，迁徙的北方象海豹中的强和弱地点忠诚度策略表现相似，但每种策略的成功在年度间有所不同，并且强烈受到气候条件的影响。强忠诚度促进了稳定的能量回报和低风险，而弱忠诚度促进了高回报和高风险。在异常的气候条件下，弱忠诚度表现优于强忠诚度，这表明地点忠诚度的进化优势可能会因环境变异性的增加而颠覆。我们强调了个体行为特化如何可能调节物种对气候变化的适应能力。
