Kuepper Nadja D, Marek Carina, Coria Nestor, Libertelli Marcela M, Quillfeldt Petra
Department of Animal Ecology & Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
Department of Animal Ecology & Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
Comp Biochem Physiol A Mol Integr Physiol. 2018 Oct;224:76-83. doi: 10.1016/j.cbpa.2018.06.018. Epub 2018 Jun 25.
Wilson's storm-petrels (Oceanites oceanicus) are the smallest marine birds breeding in Antarctica, where events like snowstorms often prevent parents from providing food daily for their offspring. To minimize energy expenses, Wilson's storm-petrel chicks can reduce their metabolism and body temperature by entering hypothermia. Hypothermia is reported to impact development, hence we hypothesized that hypothermia will be majorly used after long fasting periods. Chick development in a breeding colony of Wilson's storm-petrels on the South Shetland Islands was monitored daily during three consecutive summers by recording chicks' body mass and temperature, as well as environmental parameters. Provisioning, and body conditions were highest in 2017, and chicks became hypothermic most frequently in 2016. Body temperature was influenced by age, mass, body condition, and minimal nocturnal temperatures. While most chicks were able to maintain stable body temperatures when not fed for one day, some chicks' body temperatures decreased by up to 21 °C. Age did not differ between those two groups, but chicks maintaining their active body temperatures had higher body conditions. Snowstorms were typically followed by several days of unreliable food provisioning and continuous days of fasting. Most chicks were hypothermic during this time, and were hence able to survive periods of food shortages, reverse their low body temperatures after the next feeding event, and regain body mass. We conclude that hypothermia is a strong survival strategy to endure times of fasting, which might be necessary for Antarctic storm-petrel chicks to reach adulthood. However, in future scenarios, which may include more frequent snowstorms due to climate change, malnourishment could lead to more frequent use of hypothermia, which could affect chicks' development.
威尔逊暴风海燕（Oceanites oceanicus）是在南极洲繁殖的最小的海鸟，在那里，暴风雪等事件常常使亲鸟无法每天为幼鸟提供食物。为了将能量消耗降至最低，威尔逊暴风海燕幼鸟可以通过进入低温状态来降低新陈代谢和体温。据报道，低温会影响发育，因此我们推测，在长时间禁食后，幼鸟会大量采用低温策略。在连续三个夏天里，我们每天对南设得兰群岛上一个威尔逊暴风海燕繁殖群体中的幼鸟发育情况进行监测，记录幼鸟的体重、体温以及环境参数。2017年的食物供应和身体状况最佳，而幼鸟在2016年最频繁地进入低温状态。体温受年龄、体重、身体状况和夜间最低温度的影响。虽然大多数幼鸟在一天未进食时能够保持稳定的体温，但一些幼鸟的体温下降了多达21摄氏度。这两组幼鸟的年龄没有差异，但能保持活跃体温的幼鸟身体状况更好。暴风雪之后通常会有几天食物供应不稳定以及连续多日的禁食。在此期间，大多数幼鸟处于低温状态，因此能够在食物短缺时期存活下来，在下一次喂食后恢复低温的体温，并重新增加体重。我们得出结论，低温是一种强大的生存策略，有助于度过禁食期，这对于南极暴风海燕幼鸟成年来说可能是必要的。然而，在未来的情景中，由于气候变化可能会出现更频繁的暴风雪，营养不良可能导致更频繁地采用低温策略，这可能会影响幼鸟的发育。
