Metagenomic Profiling of Barn Owl (Tyto javanica javanica) Regurgitated Pellets Reveals Spatially Structured Environmental Microbiota in Paddy Agroecosystems.

The tropical barn owl (Tyto javanica javanica) is a major biocontrol agent against rodents in paddy fields. While raptors are frequently monitored for zoonotic diseases, they may also facilitate beneficial microbial redistribution. This study evaluated bacterial communities in barn owl regurgitated pellets to assess their role as environmental biosensors and vectors for microbe dispersal. We collected 90 fresh pellets from three paddy field locations during the growing season. Samples underwent bacterial enumeration and metagenomic sequencing of the 16S rRNA V3-V4 domains via the Illumina MiSeq platform. Results revealed significant spatial variation in bacterial communities across locations (PERMANOVA, F(2, 87) = 3.14, p < 0.05). Firmicutes (28.1%-63.2%) and Proteobacteria (17.7%-45.6%) dominated all sites. Notably, Sporosarcina sp., known for eco-friendly biocementation and soil enhancement, was highly abundant across all locations (up to 40.6%). The high abundance of Escherichia sp. at the AV site (32.1%) highlighted the pellet's ability to capture transient environmental and prey-derived coliforms. Ultimately, these pellets act as critical environmental proxies capturing localized microbiota. This supports the perspective that barn owls contribute significantly more to microbial ecological redistribution than to disease spread, offering valuable agricultural ecological services.