Bioluminescent Macaw

hey i have a question regarding the feathers. I’m trying to create realistic feathers and i attempted the texture approach but i couldnt get that shadow effect between the overlapping feathers like in this photo here

i would love to know if theres a work around for this as i am intending to animate this and i need it to be as photoreal as possible.
I tried lowering the alpha but it didnt look good
I tried using as high of a resolution as possible and it didnt work (i created each feather from scratch with hair particles)
If anyone can help me… Please do…