Tohoros 1:3-4

Tohoros 1:3

The carrion of non-kosher birds requires the intention to eat it; it must be rendered susceptible (through a liquid); it conveys food impurity in the volume of an egg; eating a quarter of a loaf in volume renders one’s body unclean for eating trumah; the volume of an olive doesn’t convey impurity in one’s throat; one who eats it need not wait until sunset to be purified; guilt is not incurred because of it for entering the Temple; it requires trumah to be burned; one who eats a limb of it alive is not subject to lashes; slaughtering it doesn’t purify it. The wings and feathers are susceptible to impurity, they convey impurity and they combine (with flesh) to form the requisite volume. The beak and claws are susceptible to impurity, they convey impurity and they combine to form the requisite volume.

Tohoros 1:4

When it comes to animals, the hide, the juice, the spices, the scraps, the bones, the sinews, the horns and the hooves combine in order to convey food impurity but not to convey neveila (carrion) impurity. Similarly, if one slaughters a non-kosher animal for a non-Jew and it’s still convulsing, it can convey food impurity but it only conveys neveila impurity after it dies or its head has been severed. More things convey food impurity than convey neveila impurity.