Max Planck Institute for Ornithology, Vogelwarte Radolfzell, Schlossallee 2, 78315 Radolfzell, Germany,
J Comp Physiol B. 2011 Jan;181(1):83-90. doi: 10.1007/s00360-010-0508-4. Epub 2010 Aug 19.
The immune system is essential for health and survival of vertebrates, yet still little is known about the ontogeny of the immune system in wild birds. The southern rockhopper penguin (Eudyptes chrysocome chrysocome) is a semi-altricial seabird with a long developmental period and reversed hatching asynchrony, favouring the survival of B-chicks. We compared leucocyte counts and baseline corticosterone levels of southern rockhopper penguin chicks under different preconditions such as sex and origin from an A- or B-egg from 4 to 51 days of age. We conducted an experiment to compare leucocyte profiles and baseline corticosterone levels in A- and B-chicks in single-egg clutches as well as in B-chicks from normal two egg-clutches (one A- and one B-egg). None of these treatments influenced leucocyte counts or corticosterone levels, indicating a similar investment in the immune system. Our main finding was an increase of leucocytes/10,000 erythrocytes with age, which was mainly caused by an increase in lymphocyte numbers. This suggests differential investment into acquired immunity at this stage of development. As the granulocyte/lymphocyte (G/L) ratio did not change with age or body condition, G/L ratios seem not to reflect stress caused by poor provisioning of penguin chicks. This was also reinforced by the decrease of plasma corticosterone levels with age. Body condition was negatively correlated with monocyte numbers, suggesting a poorer health status of penguin chicks in poorer body condition. Yet, there was no link between body condition and other leucocyte parameters, indicating that chicks in a good body condition did not additionally invest into their immune system.
免疫系统对于脊椎动物的健康和生存至关重要，但我们对于野生鸟类免疫系统的发育过程仍然知之甚少。南方凤冠企鹅（Eudyptes chrysocome chrysocome）是一种半早成性的海鸟，具有较长的发育期和孵化不同步的特点，有利于 B 雏鸟的生存。我们比较了不同条件下，即性别和 A 或 B 卵来源，从 4 到 51 日龄的南方凤冠企鹅雏鸟的白细胞计数和基础皮质酮水平。我们进行了一项实验，比较了单卵巢中 A 雏鸟和 B 雏鸟以及正常的双卵巢中（一个 A 卵和一个 B 卵）B 雏鸟的白细胞谱和基础皮质酮水平。这些处理均未影响白细胞计数或皮质酮水平，表明在免疫系统方面的投资相似。我们的主要发现是白细胞/10000 红细胞随着年龄的增加而增加，这主要是由于淋巴细胞数量的增加。这表明在这个发育阶段，获得性免疫有不同的投资。由于粒细胞/淋巴细胞（G/L）比值与年龄或身体状况无关，因此 G/L 比值似乎不能反映由于幼鸟供应不足而导致的压力。随着年龄的增加，血浆皮质酮水平的下降也证实了这一点。身体状况与单核细胞数量呈负相关，这表明身体状况较差的幼鸟健康状况较差。然而，身体状况与其他白细胞参数之间没有联系，这表明身体状况良好的幼鸟并没有额外投资于其免疫系统。
