This project is assessing microplastic pollution as an environmental justice issue through avian ecology and community-engaged research in San Antonio, Texas. Microplastics, defined as plastics 1mm-5mm in size, are prevalent in the environment. However, marginalized communities may experience a disproportionate burden of microplastic pollution because procedural injustice often results in reduced or denied services that address issues of pollution, the accumulation of road-side waste and illegal dumps, or waste management facilities being located near marginalized communities. In this project, community scientists across the city host nest boxes in their homes and monitor the breeding attempts of House Sparrows (Passer domesticus) following a modified NestWatch protocol. Members of the research team collect nestling fecal sacs and analyze them for microplastic content. We anticipate that birds nesting in areas with a higher socioeconomic status will be less exposed to microplastics and have higher breeding success than birds nesting in areas with a lower socioeconomic status. This research empowers community members to address issues of environmental justice in their neighborhoods while also increasing knowledge about an environmental contaminant of pressing concern.
150 birdhouses are currently set up across San Antonio in private homes and on UTSA campus. Community members participate in monitoring birdhouses for nests, eggs, and nestlings!
Once nestlings are ten days old, fecal samples are collected and analyzed for microplastics. Four different species have been using our birdhouses: Black-crested titmice, Carolina wrens, Bewick’s wrens, and house sparrows.
Fecal samples are digested in the lab and microplastics are extracted and counted using a microscope, lastly, types of plastics are confirmed through an FTIR analysis. (FTIR is a technique used to identify a substance’s chemical formula, and thus identify what material it is made of).
plastics photos by Anisa Riccardelli
Plastics are a ubiquitous part of daily life. Pictured above are plastics found on UTSA’s very campus. Understanding microplastic exposures in birds can help us better understand the impact of these plastics in our communities and the birds that form a part of it.
We are so grateful to all the community members who are participating in this project. Preliminary results were presented at the 142nd Annual Meeting of The American Ornithological Society in 2024, and at the Texas Chapter of the Wildlife Society Annual Meeting in 2025.