ネズミヤマシトド Geospizopsis unicolor

This common finch is found in open areas in the Andes from Venezuela to southernmost Argentina. Males are uniform bluish-gray with no distinct markings. Females in the northern part of its range are brown and streaky all over; in the south, females are grayer with fainter streaking. Both sexes have dull pinkish legs. Look for small flocks foraging on the ground in grasslands and open rocky areas, usually at elevations above 3,000 m, but descends much lower in southern South America. Sometimes mixes with other finches.