This is how the Huey, Dewey, and Louie costumes have changed over the years in the parks.

Picture As seen in Year Description
0886444290722 600 The Chantal Goya cover 1978 and 1986 These are the alternate costumes for the boys, wearing their Junior Woodchucks uniforms. Their bills are very short, they have round white eyes and eyebrows, and their tails are longer. These costumes were last seen in Walt Disney World's 15th Anniversary Parade.
HueyDeweyLouie1-93 The Twelve Days of Christmas and Campout at Walt Disney World. 1980s - 1996 The first ones had larger parrot-like eyes with larger pupils.
Kevin jonas
Disneyland 1996 - present The current ones have rounder heads and little round eyes with eyelids and heart-shaped red tongues.