This shot shows clearly some of the field marks to recognize a juvenile great blue heron. The top of the head is all dark without the wide white stripe an adult would have. The bill is two-toned instead of the mostly yellow adult bill. The stripes on the front of the neck are a bit less reliable since adults have some striping too. Juvenile striping looks different but it takes being familiar with how both stripings appear. This one was so focused on its fishing, it never noticed me above it.
Juvenile Great Blue Heron ( Ardea Herodias)