Of wire the following sizes are suitable for birds:

Number 6 Pelican.
Number 7 Wild turkey, swan.
Number 8 Eagles.
Number 9 Loon, goose, large herons.
Number 10 Seagull, large ducks, hawks, owls, and fish hawk.
Number 11 or 12 Medium size ducks, herons, and similar.
Number 13 or 14 Small ducks and grouse.
Number 15 Small herons, and medium owls.
Number 16 Doves, small owls.
Number 17 or 18 Bob white, jay, robin, snipe.
Number 19 Blackbird, waxwing, oriole.
Number 20 Bluebird, cardinal.
Number 21 to 24 Warblers, wrens, titmouse, finches.
Number 26 North American humming bird.

For quadrupeds:

Number 7 Wild cat.
Number 8 Foxes.
Number 10 Raccoon, wood chuck.
Number 11 Skunk, opossum.
Number 12 or 13 Muskrat, rabbit.
Number 14 or 15 Mink, large squirrels.
Number 17 or 18 Weasel, bull frog, and small squirrels.

These sizes are approximate, varying with size of the individual specimen and the required attitude wanted. For instance, a bird mounted with wings spread would be better for a large size wire than if in a resting position. An animal crouched does not require as heavy supports as one upright or in action. It is best to give the specimen the benefit of the doubt, as nothing is more disastrous than to have an otherwise well mounted subject sag down and spoil the entire effect from lack of sufficient mechanical support. The best wire for this purpose is annealed, galvanized iron. Larger animals require Norway iron rod in the following sizes: