Finding a cardinal's feather has no significance other that the pleasure of finding such a pretty thing. There is nothing supernatural involved.
There was/is a cardinal nearby
When you find a crow feather, it represents good health and staying away from harsh cancers and diseases.
There are Angels in your life
The blue feather is what you use to purpose to the person you like when they have a red heart.
It means a bird was just flying by and dropped a feather no omen no sign just simple as that :)
it means you will have good luvck for 100 days
it means its bad luck.
The death of your loved one is ambiguois
It means a blackbird was in the area.
It means you have a hole in your pillow or quilt.
It means that somewhere in your vicinity a fowl with white feathers lurks.
One can find the Cardinal Gate online on the Cardinal Gate website. The Cardinal Gate Online can also be found via blogs and forums dedicated to the Cardinal Gate.