Trophic relationships at a restoration reference site identify key plant resources for a declining songbird

Introduction Habitat loss and degradation threaten many taxa, and restoring habitats requires understanding how management influences resource availability for imperiled species. Restoration often focuses on plant composition, yet identifying plants that support essential trophic interactions remains a critical need. Maritime grasslands are an imperiled, understudied ecosystem where this knowledge is limited. Objectives We quantified trophic interactions at a maritime grassland restoration reference site to identify plants providing key resources for a declining omnivorous songbird, the Painted Bunting ( Passerina ciris ). Methods Using fecal DNA metabarcoding and field‐based food availability sampling, we quantified plant and insect taxa in Painted Bunting diets, evaluated seasonal diet variation relative to resource availability, and developed a restoration importance index to prioritize plant taxa in restoration. Results We found that bunting diets changed throughout the breeding season and that birds consumed food resources proportional to resource availability, suggesting that buntings do not show a strong food‐type preference. Conclusion These results demonstrate the value of incorporating trophic interactions from reference sites to guide habitat restoration for species of conservation concern and a transferable framework for restoration efforts.