Study finds that Host Phylogeny is more influential than geography in seabird Feather Mite Assemblages

A study showed that host phylogeny is a stronger determinant than geography in the composition of seabird feather mite communities. The study by Laura M. Stefan, Wolf Isbert, Elena Gómez-Díaz and four others was published on March 23.

The makeup of symbiont groups, whether they're parasites, mutualists or commensals, is influenced by various factors such as their relationship with hosts, host evolution, behavior and physical traits, as well as environmental and ecological elements like habitat and location, according to a scientific reports study. Often, closely related hosts might share similar symbionts due to shared characteristics or conditions. While some research shows that host evolution strongly influences symbiont similarities, other findings suggest environmental and ecological factors also matter. Notably, most of this research centers on internal parasites, with external parasites receiving less focus.

Symbiont groupings, including their diversity and organization, depend on a variety of influences ranging across both time and space, according to the study. The evolutionary history of hosts and the geographical distances between them are particularly crucial in this context. Seabirds and their associated feather mites present an intriguing model to delve into these aspects, given the mites' strong preference for specific hosts and their minimal mobility. Additionally, seabirds are notable for the diversity of mite species they support, and their group breeding habits create a conducive environment for symbionts to interact with multiple host species.

In a comprehensive study spanning the Atlantic Ocean and Mediterranean Sea, feather mites from 11 distinct seabird species were examined. This revealed a surprising 33 mite species, with more than half being either new or only recently identified. An interesting observation was that the mites showed a preference for specific seabird genera rather than individual species. This indicates that prior assumptions about mites preferring particular species might stem from inadequate data on closely linked host species. Furthermore, while geographical distance had some bearing on mite similarity in specific seabirds, like Cory’s shearwaters, its influence was generally limited. The overarching takeaway underscores the significance of host evolution over geography in shaping the nature and organization of these mite communities.

Nature: Laura M. Stefan, et al., Diversity and structure of feather mite communities on seabirds from the north–east Atlantic and Mediterranean Sea, Scientific Reports (2023). DOI: https://doi.org/10.1038/s41598-023-30858-8