I am currently researching Paul’s language of wakefulness and sobriety in view of the return of Christ. What a fascinating subject and I am sorry to say that there is only one serious work on this theme and it is quite old (Spiritual Wakefulness in the NT, Loevestam, 1963)!
In any case, I was interested in a comment made by A.W. Steffler regarding the use of the crane in early Christian symbolism.
“The crane became a symbol of renewal and resurrection in early Christian iconography because its migratory flight announced the coming of spring. The crane is also a model of Christian vigilance. The crane keeps itself awake by standing on one foot and holding a stone in the other. If it nods off, the stone falls and awakens it. The crane’s vigilance was extolled by Hohberg in 1675 in his book of emblems: “by night the crane a pebble gripped doth hold,/Lest sleep surprise his watch and close his eyes,/So, lest this world should lull with pomp and gold,/The Cross reminds us where our duty lies.” (Symbols of the Christian Faith, Eerdmans, 57)
So, slap a crane on your bumper – it might remind you to stay awake when driving too!