Here is today's distich by Martial, 13.70. The Romans would indeed eat peacocks and swans on special occasions. Peacocks' tongues were a proverbial delicacy.
Miraris, quotiens gemmantis explicat alas,
et potes hunc saevo tradere, dure, coco?
Here is the vocabulary:
miror - wonder at, be amazed
quotiens - as often as
gemmo - bud, put out buds
explico - unfold
ala - wing
et - and
possum - can, be able
hic - this, this one
saevus - wild, savage
trado - hand over, betray
durus - harsh, hard
cocus (coquus) - cook