Haemosporidian blood parasites are widely used in evolutionary ecological research when exploring the effects of parasites on different life-history traits of their bird hosts. However, their roles in bird migration are less studied. If these parasites deteriorate the body condition of the birds strongly, they might negatively affect the whole migration phenology and the survival of the birds as well. In our study, we tested the relationships between infection for parasite genera (Haemoproteus or Plasmodium), the three most frequent parasite lineages and body condition (body mass, fat deposit), and the timing of autumn migration in the European Robin (Erithacus rubecula). We found that mean body mass and fat scores did not differ between parasitized and non-parasitized individuals, but infected juveniles arrived later than their non-infected counterparts. The difference in the arrival time of parasitized and non-parasitized birds was greater in the case of Haemoproteus infections. However, when we analysed the effects of the distinct parasite lineages separately, we found that prevalence of parasite lineages correlated with the body mass, fat storage, and timing of autumn migration of the birds in a different direction. Our results therefore emphasize the importance of testing the impacts of the different parasites individually, because possible lineage-specific effects on bird condition during migration might exist.

在探索寄生虫对其鸟类宿主不同生活史特征的影响时，血孢子虫血液寄生虫被广泛用于进化生态研究。然而，它们在鸟类迁徙中的作用研究较少。如果这些寄生虫严重恶化鸟类的身体状况，它们可能会对整个迁徙物候和鸟类的生存产生负面影响。在我们的研究中，我们测试了寄生虫属（Haemoproteus或Plasmodium）感染、三种最常见的寄生虫谱系和身体状况（体重、脂肪沉积）与欧洲知更鸟（Erithacus rubecula ）秋季迁徙时间之间的关系）。我们发现平均体重和脂肪分数在寄生个体和非寄生个体之间没有差异，但受感染的幼体比未感染的幼体更晚到达。在Haemoproteus感染的情况下，被寄生和未寄生的鸟类到达时间的差异更大。然而，当我们分别分析不同寄生虫谱系的影响时，我们发现寄生虫谱系的流行与鸟类的体重、脂肪储存和秋季向不同方向迁移的时间相关。因此，我们的结果强调了单独测试不同寄生虫影响的重要性，因为可能存在迁移过程中对鸟类状况的谱系特异性影响。