The significance of the birds red feathers which is the prominent color of doodle's blood when he was found under the red nightshade bush.

Help me reword this sentence it doesnt make sense...

This part is two dependent clauses:

~~ which is the prominent color of doodle's blood

~~ when he was found under the red nightshade bush.


This part seems to be the complete subject, but there is no verb to complete the thought:
~~ The significance of the birds red feathers

I'd take that subject part and give it a predicate (verb plus any modifiers/complements). Then I'd take those two dependent clauses and make them into a separate sentence.

You should end up with two sentences.