The reproductive success of birds is strongly driven by environmental conditions at different time scales. Thus, during periods of low food availability, breeding success is constrained by the ability of adults to adapt their foraging effort and feeding behaviour to maintain regular incubation shifts and chick provisioning. However, while large seabirds can buffer disruptions in prey availability, the ecophysiological constraints of smaller species may limit their behavioural flexibility. By combining information on at-sea movements, foraging habitat, trophic niche, and breeding success, this study evaluated the effects of intense variability in oceanographic conditions on common diving petrels (Pelecanoides urinatrix) at the northern extent of their range in south-eastern Australia during four consecutive breeding seasons. Unusually low breeding success (6 and 0%) was observed during two years with intense heatwave events, which were associated with higher foraging effort (foraging trips twice longer) and a substantial shift in trophic niche (lower blood δ¹⁵N values). These findings suggest that common diving petrels in Bass Strait may have reached a critical threshold above which buffering the effects of environmental variability on their reproductive output is not possible. The clear cascading impacts that marine heatwaves have on zooplankton feeders illustrate the profound bottom-up effect induced by such extreme environmental variations, and suggest strong impact on higher-trophic levels. The wide, circumpolar breeding distribution of the common diving petrel, and its high sensitivity to variations in oceanographic conditions, suggest that this species may be a suitable model to study short-term and long-term behavioural responses to the effects of climate change throughout the Southern Ocean.

鸟类的繁殖成功受不同时间尺度的环境条件的强烈驱动。因此，在食物供应不足的时期，繁殖成功受到成虫适应其觅食努力和摄食行为以维持定期孵化轮班和雏鸡供应的能力的限制。然而，虽然大型海鸟可以缓冲猎物供应的中断，但较小物种的生态生理限制可能会限制它们的行为灵活性。通过结合海上运动、觅食栖息地、营养生态位和繁殖成功的信息，本研究评估了海洋条件的剧烈变化对常见潜水海燕（Pelecanoides urinatrix）的影响。）在连续四个繁殖季节期间在澳大利亚东南部的北部范围内。在发生强烈热浪事件的两年中观察到异常低的繁殖成功率（6% 和 0%），这与更高的觅食努力（两次更长的觅食旅行）和营养生态位的重大转变（更低的血液δ ¹⁵N 值）。这些发现表明，巴斯海峡常见的潜水海燕可能已达到临界阈值，超过该阈值就不可能缓冲环境变化对其繁殖输出的影响。海洋热浪对浮游动物饲养者的明显连锁影响说明了这种极端环境变化引起的深刻的自下而上的影响，并表明对较高营养级的影响很大。普通潜水海燕的广泛、极地繁殖分布及其对海洋条件变化的高度敏感性表明，该物种可能是研究对整个气候变化影响的短期和长期行为反应的合适模型。南部海洋。