Around 1985, the Cardinal Bird's head began to be used as a logo on its own.
Initially, the head mirrored the head on the "full" mascot.
The image above is from the 1985 basketball media guide. For comparison, the image below is from the program for the UofL-Southern Mississippi basketball game, February 24, 1988.
In 2000, the university announced "enhanced athletic marks."
The black lining around his beak and eye was streamlined and his head feathers took on a more aerodynamic appearance. The shape of his beak was also modified slightly.
An alternate version, with a wing, was included in the new trademarked logos.