Maternal effects are ubiquitous. Yet, the pathways through which maternal effects occur in wild mammals remain largely unknown. We hypothesise that maternal immune transfer is a key mechanism by which mothers can affect their offspring fitness, and that individual variation in maternally derived antibodies mainly depends on a mother's characteristics and the environmental conditions she experiences. To test this, we assayed six colostrum-derived antibodies in the plasma of 1447 neonates in a wild red deer population. Neonatal antibody levels were mainly affected by maternal genes, environmental variation and costs of prior reproductive investment. We found consistent heterogeneity in maternal performance across traits, with mothers producing the heaviest calves also having calves with more antibodies. Unexpectedly, antibody levels were not associated with calf survival. We provide a unique example of how evolutionary theory on maternal effects can be used to gain insight into the causes of maternal effects in wild populations.

中文翻译：

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母源转移抗体对马鹿母源性能的影响

母体效应无处不在。然而，在野生哺乳动物中发生母体效应的途径仍然很大程度上未知。我们假设母体免疫转移是母体影响后代健康的关键机制，母源抗体的个体差异主要取决于母亲的特征和她所经历的环境条件。为了测试这一点，我们在野生马鹿种群的 1447 名新生儿的血浆中检测了六种源自初乳的抗体。新生儿抗体水平主要受母体基因、环境变化和先前生殖投资成本的影响。我们发现不同性状的母体表现存在一致的异质性，母体生产最重的小牛，小牛也有更多的抗体。不料，抗体水平与小牛存活率无关。我们提供了一个独特的例子，说明如何使用关于母体效应的进化理论来深入了解野生种群中母体效应的原因。