Bunting birds belong to that group of small songbirds whose calls are quick, bright, and easily lost in a mix unless you place them carefully. Bird-call editors usually pan them slightly off-centre and tuck them under a wider ambience bed, so they read as detail rather than a foreground subject.
You will find 3 bunting bird clip here, including male territorial calls, female chirping, evening roost noises, and a few northern cardinal song passes that sit nicely alongside them in mixed-flock edits. Nature documentaries, garden b-roll, and animated bird scenes all benefit. Free to take as MP3, no signup needed, no licence chase.