• Kerry Schutten/University of Guelph
• Akshaya Chandrashekar/University of Guelph
• Brian Stevens/University of Guelph
• Laura Dougherty/University of Guelph
• Jennifer Provencher/Environment and Climate Change Canada
• Claire Jardine/University of Guelph

Plastic waste has become one of the most ubiquitous and persistent pollutants in our modern environment. Plastic pollution presents many potential avenues of risk for wildlife, including entanglement in macroplastics, ingestion of microplastics, and exposure to plastic-derived chemicals or absorbed environmental contaminants. Understanding which species and environments are at highest exposure to plastic pollution is a critical first step in investigating the health impacts of plastic exposure, identifying conservation priorities, and informing waste management policy.

Between 2020-2022, deceased wild birds were collected across Ontario as part of routine passive disease surveillance through the Canadian Wildlife Health Cooperative. All individuals were necropsied, and data on location, morphometrics, demographics, co-morbidities, and cause of death were collected. The upper gastrointestinal tract (esophagus, proventriculus and ventriculus) were examined for visible plastics and other anthropogenic particles >2 mm in size, using standard techniques.

A total of 318 birds across 48 species were included in this analysis. Twenty-five individuals (% Frequency Occurrence = 7.9) contained visible anthropogenic particles in their upper gastrointestinal tract, with prevalence varying across species. Gulls and waterfowl were the most frequently represented species groups.

A variety of bird species ingest and retain anthropogenic particles in the wild, and species-level factors such as foraging technique, physiology, and behaviour are hypothesized to influence exposure and ingestion risk. Ongoing investigation will assess potential health impacts of plastic ingestion in Ontario bird species.