Black-crowned Night Heron (immature)

Black-crowned Night-Herons are small herons with rather squat, thick proportions. They have thick necks, large, flat heads, and heavy, pointed bills. The legs are short and, in flight, barely reach the end of the tail. The wings are broad and rounded.

Color Pattern
Adults are light-gray birds with a neatly defined black back and black crown. Immatures are brown with large white spots on the wings and blurry streaks on the underparts. Adults have all-black bills; immatures have yellow-and-black bills.

http://www.allaboutbirds.org/guide/black-crowned_night-heron/id