Tohoros 1:1-2

Tohoros 1:1

There are 13 things about the carrion of kosher birds: it must be intended for food; It need not be rendered susceptible (through a liquid); it conveys food impurity in the volume of an egg; it conveys impurity in one’s throat in the volume of an olive; one who eats it must wait until sunset (to be purified); one is liable because of it for entering the Temple; trumah is burned because of it; one who eats a limb of it alive receives 40 lashes; slaughtering it or nipping off its head purifies it even if it’s found to be a treifa; this is the opinion of Rabbi Meir. Rabbi Yehuda says that these things don’t purify it. Rabbi Yosi says that slaughter purifies it but nipping the head doesn’t.

Tohoros 1:2

Wings and feathers are susceptible to impurity and they convey impurity but they don’t combine (with flesh) to form the requisite volume. Rabbi Yishmael says that feathers do combine. Beaks and claws are susceptible to impurity and convey impurity; they also combine to form the requisite volume. Rabbi Yosi says that the tips of wings and the ends of tails combine to form the requisite volume because these things are left on fattened birds.