Feathers are the habitat of a myriad of organisms, from fungi and bacteria to lice and mites. Although most studies focus on specific taxa and their interaction with the bird host, anecdotal data glimpse feathers as holders of a system with its own ecology, what we call here the stylosphere. A major gap in our knowledge of the stylosphere is the ecology of the total abundance of microorganisms, being also rare to find studies that analyze abundance of more than one group of microorganisms at the bird interspecific level. Here, we quantified bacterial and fungi abundances through qPCR on the wing feathers of 144 birds from 24 passerine and one non-passerine bird species from three localities in Southern Spain. Bacteria and fungi abundances spanned three orders of magnitude among individual birds, but were consistent when comparing the right and the left wing feathers of individuals. Sampling locality explained ca. 14% of the variation in both bacteria and fungi abundances. Even when statistically controlling for sampling locality, microbial abundances consistently differed between birds from different species, but these differences were not explained by bird phylogeny. Finally, bird individuals and species having more bacteria also tended to held larger abundances of fungi. Our results suggest a quite complex explanation for stylosphere microorganisms’ abundance, being shaped by bird individual and species traits, as well as environmental factors, and likely bacteria–fungi interactions.

羽毛是无数生物的栖息地，从真菌和细菌到虱子和螨虫。尽管大多数研究都集中在特定的分类群及其与鸟类宿主的相互作用上，但轶事数据将羽毛视为具有自己生态系统的系统的持有者，我们在这里称之为风格圈。我们对花柱圈知识的一个主要差距是微生物总丰度的生态学，也很少有研究在鸟类种间水平上分析一组以上微生物的丰度。在这里，我们通过 qPCR 对来自西班牙南部三个地方的 24 只雀鸟和 1 只非雀鸟的 144 只鸟的翅膀羽毛进行了定量 PCR。细菌和真菌的丰度在个体鸟类中跨越三个数量级，但在比较个体的右翼和左翼羽毛时是一致的。抽样地点解释了大约。细菌和真菌丰度变化的 14%。即使在对采样地点进行统计控制时，来自不同物种的鸟类之间的微生物丰度也始终存在差异，但鸟类系统发育无法解释这些差异。最后，具有更多细菌的鸟类个体和物种也往往拥有更多的真菌。我们的研究结果提出了对花柱圈微生物丰度的相当复杂的解释，这是由鸟类个体和物种特征、环境因素以及可能的细菌-真菌相互作用形成的。即使在对采样地点进行统计控制时，来自不同物种的鸟类之间的微生物丰度也始终存在差异，但鸟类系统发育无法解释这些差异。最后，具有更多细菌的鸟类个体和物种也往往拥有更多的真菌。我们的研究结果提出了对花柱圈微生物丰度的相当复杂的解释，这是由鸟类个体和物种特征、环境因素以及可能的细菌-真菌相互作用形成的。即使在对采样地点进行统计控制时，来自不同物种的鸟类之间的微生物丰度也始终存在差异，但鸟类系统发育无法解释这些差异。最后，具有更多细菌的鸟类个体和物种也往往拥有更多的真菌。我们的研究结果提出了对花柱圈微生物丰度的相当复杂的解释，这是由鸟类个体和物种特征、环境因素以及可能的细菌-真菌相互作用形成的。