RT Journal Article T1 High diversity and low genetic structure of feather mites associated with a phenotypically variable bird host A1 Fernández González, Sofía A1 Pérez Rodríguez, Antón David A1 Proctor, Heather C. A1 Hera Fernández, Iván de la A1 Pérez Tris, Javier AB Obligate symbionts may be genetically structured among host individuals and among phenotypically distinct host populations. Such processes may in turn determine within-host genetic diversity of symbionts, which is relevant for understanding symbiont population dynamics. We analysed the population genetic structure of two species of feather mites (Proctophyllodes sylviae and Trouessartia bifurcata) in migratory and resident blackcaps Sylvia atricapilla that winter sympatrically. Resident and migratory hosts may provide mites with habitats of different qualities, what might promote specialization of mite populations. We found high genetic diversity of within-host populations for both mite species, but no sign of genetic structure of mites between migratory and resident hosts. Our results suggest that, although dispersal mechanisms between hosts during the non-breeding season are unclear, mite populations are not limited by transmission bottlenecks that would reduce genetic diversity among individuals that share a host. Additionally, there is no evidence that host phenotypic divergence (associated with the evolution of migration and residency) has promoted the evolution of host-specialist mite populations. Unrestricted dispersal among host types may allow symbiotic organisms to avoid inbreeding and to persist in the face of habitat heterogeneity in phenotypically diverse host populations. PB Cambridge University Press SN 0031-1820, ESSN: 1469-8161 YR 2018 FD 2018-01-17 LK https://hdl.handle.net/20.500.14352/12083 UL https://hdl.handle.net/20.500.14352/12083 LA eng NO Ministerio de Ciencia e Innovación (España) NO Ministerio de Educación y Ciencia (España) NO Gobierno Vasco (España) NO Natural Sciences and Engineering Research Council of Canada (NSERC) DS Docta Complutense RD 3 abr 2025