There's something about the smell of Dead Peppers that overrides common sense in even the biggest or most intelligent Chocobo.
You just got to have it... even more than the most fresh Chysahl...
Unfortunately, well, peppers are peppers and there's that little thing that you get from chomping down a whole fresh pepper.
Taross is mine
Art by Royalty
Chocobo belong to SquareEnix
This is a special Dead Pepper. https://youtu.be/EXfBhrnj2Xs?t=5m5s
Link
Felthry
You know, birds can't actually taste the spiciness of peppers. That's actually the evolutionary origin of said spiciness: the plants' seeds are spread by birds, and the spiciness stops other animals (which might digest the seeds or just not spread them far enough) from eating them.