how come all the peacock I see in the stores is so thin compared to what I used to be able to find? (I live in Colorado).

I used to be able to find thick peacock that was good for tying #12 & #14 nymphs. I can not find it anywhere nowadays. I have an easier time finding peacock for #18 & #20 nymphs.

Is there a "genetic " peacock that is being bread or something?