Data supporting: Migratory songbirds as potential ectozoochorous protist dispersal vectors

This file provides data pertaining to diatoms (Bacillariophyceae) found on four migratory songbird species (Turdidae). The XLSX file contains two sheets: 1) data associated with the submitted manuscript and 2) associated metadata.Associated manuscript: https://doi.org/10.1002/ece3.72703 (Fischer et al. 2025 Ecology and Evolution)We present observations of songbirds hosting diatoms (microalgae with silica cell walls) and discuss the potential implications of migratory birds as dispersal vectors. Many microorganisms, including diatoms, are thought to be cosmopolitan due to their small sizes and lack of dispersal limitations, but recent evidence suggests that some diatoms may exhibit population structuring and even endemism. However, the spatial distributions and dispersal mechanisms of diatom populations and species are still not well understood, and thus continue to fuel debate and research. Although there is a small-but-growing body of literature implying animal-mediated diatom dispersal, past studies have focused on aquatic animals with few examples from terrestrial species. We describe an unexpected diversity and abundance (224 individuals of 25 genera) of diatoms attached to the tails of four terrestrial, migratory songbirds in the thrush (Turdidae) family. The thrushes we studied (American Robin, Hermit Thrush, Swainson's Thrush, Wood Thrush) have diverse migration strategies and include species that migrate across continents. Thus we believe our observations highlight substantial potential for songbird-mediated diatom dispersal across a large spatial scale.Each row represents one sample (total of 7 samples). Columns A:F describe bird specimens and sampling information. Columns G:H describe summaries of overall diatom contents in each sample. Finally, columns I:OX describe each individual diatom (including whole and broken diatoms), and indicate genus (if identified), unknown diatoms (diatoms in girdle view, distorted, etc.), and fragmented diatoms (broken and thus not identified). Thus, each row (sample) has a different number of filled columns depending on how many diatoms were observed per sample. Full metadata are included as a tab in the file.