Heterothermy and torpor as energy saving strategies in Antarctic storm-petrel nestlings

异温和麻木作为南极风暴海燕雏鸟的节能策略

• 批准号: 257052966
• 负责人: Professorin Dr. Petra Quillfeldt, Ph.D.
• 金额: --
• 依托单位: ArbeitsgruppeTierökologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/257052966?language=en
• 关键词: Heterothermy; torpor; energy; saving; strategies

Wilsons storm petrels Oceanites oceanicus are the smallest endotherm breeding in the Antarctic. Given their small size and thus limited energy storage capacities, Wilsons storm petrels need to use efficient strategies to cope with both predictable and unpredictable food shortages. Strong fluctuations in food availability have been observed both within and among breeding seasons in this species. In the present study, we aim to study how Wilsons storm-petrel nestlings use heterothermy as a physiological strategy to optimize energetic investment and torpor as a strategy to ensure survival during unpredictable food shortages. We will test how body temperature and resting metabolic rate are determined by the nutritional state of nestlings, and if this is modulated by ambient temperature. As an adaptation to predictable differences in food availability, we will study daily rhythms of body temperature and resting metabolic rate. We will test if Wilsons storm-petrel nestlings strategically down-regulate their body temperature and resting metabolic rate during daytime when adults cannot deliver food. We will further study causes and consequences of individual differences in heterothermy of nestlings. We expect compromised body functions such as growth and investment into immunology in relation to decreased body temperatures and more use of torpor in chicks provisioned less frequently by their parents. Thus, heterothermy in Wilsons storm-petrel chicks may have fitness consequences through a trade-off between reducing energetic costs and investing in body functions which ultimately determine the chances for survival to breeding. As an adaptation to predictable differences in food availability, we will study heterothermy of chicks during severe weather events such as snow storms, which are predicted to become more frequent and often result in blocking of nests. The study therefore has implications for the adaptation of the species to climate change, both in relation to reduced food availability, especially reduced stocks of Antarctic krill, and increased snow storm frequencies.

威尔逊风暴海燕 Oceanites oceanicus 是南极洲最小的恒温繁殖动物。鉴于威尔逊风暴海燕体型较小，能量存储能力有限，它们需要使用有效的策略来应对可预测和不可预测的食物短缺。在该物种的繁殖季节内和繁殖季节之间，观察到食物供应量的剧烈波动。在本研究中，我们的目标是研究威尔逊风暴海燕雏鸟如何利用异温作为一种生理策略来优化能量投入，以及如何利用麻木作为一种策略来确保在不可预测的食物短缺期间的生存。我们将测试雏鸟的营养状态如何决定体温和静息代谢率，以及这是否受到环境温度的调节。为了适应食物供应的可预测差异，我们将研究体温和静息代谢率的每日节律。我们将测试威尔逊风暴海燕雏鸟是否会在白天成虫无法提供食物时策略性地下调体温和静息代谢率。我们将进一步研究雏鸟异温性个体差异的原因和后果。我们预计，由于父母喂食次数较少的雏鸡，体温下降和更多地使用麻木状态，身体功能（例如生长和免疫学投入）会受到损害。因此，威尔逊风暴海燕雏鸟的异温可能会通过降低能量成本和投资身体功能之间的权衡而产生健康后果，而身体功能最终决定生存和繁殖的机会。为了适应可预测的食物供应差异，我们将研究暴风雪等恶劣天气事件期间雏鸡的异温性，预计暴风雪会变得更加频繁，并经常导致巢穴堵塞。因此，这项研究对该物种对气候变化的适应具有影响，既与食物供应量的减少有关，特别是南极磷虾库存的减少，又与暴风雪频率的增加有关。