Year: 2026
Type: article
Abstract: Microplastic (MP) pollution is an emerging global concern, yet little is known about the exposure of terrestrial birds to MPs or how species-specific traits influence exposure. We used a traits-based approach to investigate the relationship between foraging strategies (defined by diet type and feeding behavior) and MP ingestion in terrestrial birds. We collected gastrointestinal (GI) tracts from 113 birds representing nine species in Texas, United States and analyzed them for MPs. We characterized MPs and identified represented polymer types. We found MPs in 65% of birds, with MP counts ranging from 0 to 20 per bird. Average MP counts varied significantly by species; Great-tailed Grackles ( Quiscalus mexicanus ), a ground foraging omnivore, exhibited the highest counts (5.92 MPs per bird), and Nashville Warblers ( Leiothlypis ruficapilla ), a foliage gleaning insectivore, the lowest (0.42 MPs per bird). Purple Martins ( Progne subis ), an aerial insectivore, and Cedar Waxwings ( Bombycilla cedrorum ), a frugivore, also had relatively high exposure rates. Across all species, fibers were the predominant MP type (75%), with polyester identified as the most common polymer. These results suggest that dietary breadth (i.e., generalist vs. specialist) and foraging location (e.g., ground vs. above ground vs. aerial) are important predictors of MP exposure in terrestrial birds. They also provide insight into potential exposure pathways, not only for birds but also for other animals including humans. In so doing, our results allow us to predict exposure risk of other species, and thus have broad application for strategies that aim to reduce environmental impacts of MPs.
Language: English
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7169815412