Simpson Matthew D, Dickerson Ashton L, Chiaradia Andre, Davis Lloyd, Reina Richard D
School of Biological Sciences Monash University Clayton Victoria Australia.
Leibniz-Institute of Freshwater Ecology and Inland Fisheries Berlin Germany.
Ecol Evol. 2025 Jan 11;15(1):e70787. doi: 10.1002/ece3.70787. eCollection 2025 Jan.
Understanding the relative contributions of environmental, behavioural and social factors to reproductive success is crucial for predicting population dynamics of seabirds. However, these factors are often studied in isolation, limiting our ability to evaluate their combined influence. This study investigates how marine environmental variables, foraging behaviour and social factors (divorce), influence reproductive success in little penguins () over 13 breeding seasons. By examining these factors together, we aimed to identify which is the most reliable predictor of population-level reproductive success. We found that divorce rate was the most consistent predictor of reproductive success, with lower annual rates of divorce preceding the breeding season associated with higher hatching and fledging success. Foraging trip duration also influenced reproductive success, but in contrasting ways: Longer trips during egg incubation were linked with increased hatching success, while shorter trips after hatching led to higher fledging success. Marine environmental conditions had unexpected effects, with a lower Southern Oscillation Index (SOI) correlating with improved hatching and fledging success, in contrast to previous research, while sea surface temperature (SST) had no significant effect on reproductive success. This highlights the complexity of seabird breeding responses to large-scale oceanographic indices, suggesting SOI and SST are generally less reliable measures to use as indicators of reproductive success. Our results suggest that divorce rate could serve as a valuable, noninvasive index of reproductive success in seabirds.
了解环境、行为和社会因素对繁殖成功率的相对贡献对于预测海鸟种群动态至关重要。然而，这些因素通常是单独研究的，这限制了我们评估它们综合影响的能力。本研究调查了海洋环境变量、觅食行为和社会因素（离婚）如何在13个繁殖季节中影响小企鹅（）的繁殖成功率。通过综合考察这些因素，我们旨在确定哪个是种群水平繁殖成功率最可靠的预测指标。我们发现离婚率是繁殖成功率最一致的预测指标，繁殖季节前较低的年离婚率与较高的孵化和出飞成功率相关。觅食行程持续时间也影响繁殖成功率，但方式不同：卵孵化期间较长的行程与孵化成功率增加有关，而出飞后较短的行程则导致较高的出飞成功率。海洋环境条件产生了意想不到的影响，与之前的研究相反，较低的南方涛动指数（SOI）与提高的孵化和出飞成功率相关，而海面温度（SST）对繁殖成功率没有显著影响。这凸显了海鸟繁殖对大规模海洋学指数反应的复杂性，表明SOI和SST通常作为繁殖成功率指标的可靠性较低。我们的结果表明，离婚率可以作为海鸟繁殖成功率的一个有价值的、非侵入性指标。
