Black-crowned Night Herons have red eyes, a black crown and white plume, a short white to pale gray neck, a very pale gray belly, a solid black back and pale yellow legs that a red during breeding season. Black-crowned Night Herons have a black bill that is shorter and more slender than a Yellow-crowned Night Heron. They appear chunky and squat compared to a Yellow-crowned Night Heron.
Yellow-crowned Night Herons have orange-red eyes, a white crown with a slight yellow tint & white plume, they have a black head with a white cheek patch, a long slender gray neck and belly, a gray back with a pattern and yellow legs. Yellow-crowned Night Herons have a thick black long bill. They appear slender compared to a Black-crowned Night Heron.
Juvenile Black-crowned Night Herons are chunky and squat like the adults and have short necks. The bill of a juvenile is dark on top and green to yellowish on the bottom, the lores are sometimes a greenish color and the wings have large white spots on a brown back.
Juvenile Yellow-crowned Night Herons are slender in appearance and have long slender necks. The bill of a juvenile is mostly black and the back and wings have fine spots and the overall color is darker than a juvenile Black-crowned Night Heron.