The landscape of Piers Plowman teems with ‘fleynge foweles’ (8.54). This essay argues that the hawk Langland could have seen circling high over feeld and wildernesse makes repeated appearances in different guises, and that its literary origins almost certainly lie in Hugh of Fouilloy's Aviarium. Depicting ‘uita actiua’ with the emblem of the hawk in its prologue miniature (Figure 5.1), the iconography alone of the Aviarium allows us to see at the outset how Langland could have accessed such imagery for his ‘Activa Vita’, Haukyn, whose name has long puzzled critics but whose cote is also his ‘plumage’. Hugh's text illuminates in less obvious ways; once we understand his hawk, fresh interpretations of other vexed areas of our poem are released. After a brief look at the Aviarium, I discuss Haukyn and the nature of hawks from their names, before analysing the poet's presentation of Mede, the Deadly Sins (Envy, Covetise and Sleuthe), and Piers/Perkyn. I then turn to Haukyn himself before drawing my conclusions. The aim is to trace a constellation of hawks by identifying each, and clarifying the relation of one to another; and to sharpen our appreciation of Langland's resources – learning, wit, imagination, compassion, humour – in using hawks, and birds in general, to articulate a major line of argument which involves seeing pardons as lures or traps. In revising his B text (perhaps incompletely) Langland removed Piers's tearing of the pardon, Haukyn's name and many associated hawking terms, and two citations of ‘Ne soliciti sitis’ marking their parallel conversions, and I suggest some reasons for why he did so.