Complex sentence: The little bunting ("Emberiza pusilla") is a passerine bird belonging to the bunting and American sparrow family (Emberizidae), a group most modern authors separate from the true finches (Fringillidae).
Split into simpler sentences: The little bunting ("Emberiza pusilla") is a passerine bird. It belongs to the bunting and American sparrow family (Emberizidae), a group separated by most modern authors from the true finches (Fringillidae).