"Acquire Buzzard parts" is an objective in the sidequest You Are Cordially Invited: Party Prep in Borderlands 2
Walkthrough[edit]
Head over to the Buzzard Academy. While this means you will be fighting Bandits along with Buzzards, this puts in a great place to encounter Buzzards. Meaning it will be very simple for you to just find and destroy 3 buzzards with plenty of cover against them.