Diving Physiology and Behavior of Emperor Penguins

帝企鹅Aptenodytes forsteri是南极生态系统中首屈一指的鸟类潜水员和顶级捕食者。500米潜水员在海上觅食时的常规发生是一个生理和行为之谜。这个项目的目标是解决帝企鹅如何以及为什么潜水那么深和那么长时间。该项目研究了帝企鹅潜水生物学的四个主要主题：压力耐受性，氧气储存管理，潜水低氧血症/缺血的终末器官耐受性，以及深潜觅食行为。这些主题与皇帝作为南极生态系统中顶级捕食者的作用有关，也与潜水生理学中的关键概念有关，包括减压病，氮麻醉，浅水停电，低氧耐受性和有氧潜水时间的延长。将检验以下假设：1）帝企鹅的氮麻醉和减压病的预防是通过抑制深度肺气体交换来实现的。2)浅水区不会发生黑视，因为大脑对低氧血症的耐受性更强，而在深潜时，则是因为在最后上升时肺部气体交换的恢复。3)血氧储存的消耗率是潜水深度和心率的函数。4)有氧潜水极限（ADL）反映了运动肌肉中乳酸积累的开始，而不是所有氧储存的完全耗尽。5)组织抗氧化能力和自由基清除酶活性的提高可以防止潜水过程中发生的常规缺血/再灌注。6)在深潜期间，南极银鱼，Pleuorogramma anacuticum，是帝企鹅的主要猎物。除了对以下假设进行评估外，该项目还在若干领域产生了更广泛的影响，如与外国和国家机构和组织的伙伴关系（例如，日本国家极地研究所、墨西哥东北部研究中心、国家地理、德克萨斯大学西南医学中心和海洋世界）。参与国家地理电视纪录片将为公众提供独特的教育机会;发展最先进的技术（例如，血氧电极记录仪、血液采样器和微型数码相机）将为该小组和其他人的未来研究奠定基础; B15冰山对帝企鹅繁殖成功的影响将继续在罗斯海帝企鹅殖民地的几个计划实地考察期间进行人口普查。

The emperor penguin, Aptenodytes forsteri, is the premier avian diver and a top predator in the Antarctic ecosystem. The routine occurrence of 500-m diver during foraging trips to sea is both a physiological and behavior enigma. The objectives of this project address how and why emperors dive as deep and long as they do. The project examines four major topics in the diving biology of emperor penguins: pressure tolerance, oxygen store management, end-organ tolerance of diving hypoxemia/ischemia, and deep-dive foraging behavior. These subjects are relevant to the role of the emperor as a top predator in the Antarctic ecosystem, and to critical concepts in diving physiology, including decompression sickness, nitrogen narcosis, shallow water blackout, hypoxemic tolerance, and extension of aerobic dive time. The following hypotheses will be tested: 1) Prevention of nitrogen narcosis and decompression sickness in emperor penguins is achieved by inhibition of pulmonary gas exchange at depth. 2) Shallow water black out does not occur because of greater cerebral hypoxemic tolerance, and, in deep dives, because of resumption of pulmonary gas exchange during final ascent. 3) The rate of depletion of the blood oxygen store is a function of depth of dive and heart rate. 4) The aerobic dive limit (ADL) reflects the onset of lactate accumulation in locomotory muscle, not total depletion of all oxygen stores. 5) Elevation of tissue antioxidant capacity and free-radical scavenging enzyme activities protect against the routine ischemia/reperfusion which occur during diving. 6) During deep dives, the Antarctic silverfish, Pleuorogramma antarcticum, is the primary prey item for emperors. In addition to evaluation of the hypotheses below, the project has broader impacts in several areas such as partnership with foreign and national institutes and organizations (e.g., the National Institute of Polar Research of Japan, Centro de Investigacioines del Noroeste of Mexico, National Geographic, the University of Texas Southwestern Medical Center, and Sea World). Participation in National Geographic television documentaries will provide unique educational opportunities for the general public; development of state-of-the-art technology (e.g., blood oxygen electrode recorders, blood samplers, and miniaturized digital cameras) will lay the groundwork for future research by this group and others; and the effects of the B15 iceberg on breeding success of emperor penguins will continue to be evaluated with population censuses during planned fieldwork at several Ross Sea emperor penguin colonies.