 Young birds have yellower underparts, and a duller indistinct head pattern.North Nicaragua birds, "M. l. nigrior", have a much broader black breast spot than the nominate Costa Rican form, and the northernmost of the three subspecies, "M. l. occipitalis", has a grey crown stripe, obvious yellow supercilium, and very small breast spot.White-eared ground sparrow calls include a thin "tsip".