Ask the Past teaches us how to intoxicate waterfowl.

“First clean, and then steep in clear Water, for full 4 hours, the Roots, Leaves, and Seeds of the herb Bellenge; then boil them in the same Water, till it is almost all evaporated; and after it is cold, throw it in the places where the Fowls frequent, who, eating eagerly of it, will be made so drunk as to be readily taken; but no time must be lost in catching them, for they will soon recover.”

The Complete Vermin-Killer (1777)

addendum: the erudite Heath points out (with no less authority than Robert Lowell) that one can also intoxicate fowls after killing them:

“Your stuffed duck craned toward Harvard from my trunk:
its bill was a black whistle, and its brow
was high and thinner than a baby’s thumb;
its webs were tough as toenails on its bough.
It was your first kill: you had rushed it home,
pickled in a tin wastebasket of rum�”

“To Delmore Schwartz,” Robert Lowell