Dipping into Robert Burton’s The Anatomy of Melancholy, which celebrates its inexhaustible 400th year this year, I find in the glossary castril (kestrel) and tassel (tiercel, a male falcon).
“[…]he is nobody that in the season hath not a hawk on his fist. […] The Persian kings hawk after butterflies with sparrows made to that use, and stares [starlings]; lesser hawks for lesser games they have, and bigger for the rest, that they may produce their sport to all seasons. The Muscovian emperors reclaim eagles to fly at hinds, foxes, etc., and such a one was sent for a present to Queen Elizabeth; some reclaim ravens, castrils, pies [magpies, I think], etc, and man them for their pleasures.”
Backyard and Beyond 
Wow! The Anatomy of Melancholy is the under appreciated family attic of English. More strangeness and sound strangling language of any english book. Never expected it in this context. Made my day!