"Tie two birds together, and even though they have four wings, they cannot fly." - The Blind Man, Circle Of Iron
Wait a minute! Supposing *two* swallows carried it together!
G1: Nooo..... They'd have to have it on a line...
G2: Well, simple! They'd just use a strand of creeper!
G1: What, held under the dorsal guiding feathers?
G2: Well, why not? "Monty Python and the Holy Grail"