First Test is the Waddles and Quacks Test… if it walks like a Duck and talks like a Duck…and if I still don’t know: I look at feet…if they are webbed like Duck feet …well?
But the Final Test is the Feather Test: “Waterfowl have three types of feathers: contour, flight, and down. Contour feathers collectively serve as a protective outer shell. Each feather is composed of a central shaft with a continuous series of paired vanes that line up on opposite sides of the shaft.
Located on a bird’s wings and tail, flight feathers are a variation of contour feathers that are designed to withstand the stress and strain of flight. Because they must support a bird’s weight in flight, they are connected directly to ligaments or bone for greater structural integrity. Unlike body feathers, flight feathers have vanes of unequal width and are always narrower on their leading edge.
Down feathers serve as an inner layer of insulation that traps warm air against a bird’s body. They have a short shaft and no interlocking barbules, giving them a light, fluffy appearance. Before the advent of modern synthetic insulation, duck and goose down was widely used by people to line blankets, clothing, and sleeping bags. Even today, the warmth-to-weight ratio of eider (northern sea duck) down is still unsurpassed when dry.” (Feather Information: David Brakhage, ‘Ducks Unlimited’)
This feather thing kind of serves as Duck Criticism or a Duck Hermeneutic in difficult identity situations when the walking, talking and webfoot tests are not enough. Duck Tests often work on people as well.
“Look at the birds of the air: they neither sow nor reap nor gather into barns, and yet your heavenly Father feeds them. Are you not of more value than they?” Jesus