Mishnah Taharos 1:1: Thirteen matters regarding the carcass of a pure fowl: it requires thought [i.e. one must initially think to use it for food, in order for it have the impurity of foods]; and it does not necessitate becoming primed [for impurity, unlike other foods, which are primed for impurity when they become wet]; and it renders foods impure [upon contact] when it has [at least the volume] equivalent to an egg; and [it renders one impure] while it is being swallowed when it has [at least the volume] equivalent to an olive; and one who eats it requires [waiting until] sunset [on the day of his immersion before he becomes pure again]; and [if rendered impure] by it, one would be liable for entering the temple; and [one rendered impure by it renders terumah impure, such that the] terumah needs to be burned on its account; and one who eats a limb taken from it while alive endures the forty [lashes]. According to Rabbi Meir, its slaughter or its melikah [ritual killing of fowl brought as sacrifices in the temple] purify [the pure fowl, if it was discovered to have been] a treifah [an animal which will not survive, and is generally rendered impure and cannot be eaten]. Rabbi Yehuda says: they do not purify. Rabbi Yose says: its slaughter purifies, but its melikah does not. [The first nine of the thirteen matters are listed in this Mishna; the final four appear in the following Mishna.]

שְׁלשָׁה עָשָׂר דָּבָר בְּנִבְלַת הָעוֹף הַטָּהוֹר. צְרִיכָה מַחֲשָׁבָה, וְאֵינָהּ צְרִיכָה הֶכְשֵׁר, וּמְטַמָּא טֻמְאַת אֳכָלִין בְּכַבֵּיצָה, וְכַזַּיִת בְּבֵית הַבְּלִיעָה, וְהָאוֹכְלָהּ טָעוּן הֶעֱרֵב שֶׁמֶשׁ. וְחַיָּבִים עָלֶיהָ עַל בִּיאַת הַמִּקְדָּשׁ, וְשׂוֹרְפִין עָלֶיהָ אֶת הַתְּרוּמָה. וְהָאוֹכֵל אֵבָר מִן הַחַי מִמֶּנָּה סוֹפֵג אֶת הָאַרְבָּעִים. שְׁחִיטָתָהּ וּמְלִיקָתָהּ מְטַהֲרוֹת אֶת טְרֵפָתָהּ, דִּבְרֵי רַבִּי מֵאִיר. רַבִּי יְהוּדָה אוֹמֵר, אֵינָן מְטַהֲרוֹת. רַבִּי יוֹסֵי אוֹמֵר, שְׁחִיטָתָהּ מְטַהֶרֶת, אֲבָל לֹא מְלִיקָתָהּ:

Mishnah Taharos 1:2: The wings and the feathers [of the carcass of a pure fowl] can be rendered impure and can render [other items] impure, and they are not added together [to reach a volume measure sufficient for causing impurity]. Rabbi Yishmael says: the feather is added [to complete the sufficient measure]. The beak and the talons render impure and they are added together. Rabbi Yose says: even the tips of the wings and the tip of the tail are added together, as they are left on the fatted [birds, for serving].

הַכְּנָפַיִם וְהַנּוֹצָה, מִטַּמְּאוֹת וּמְטַמְּאוֹת וְלֹא מִצְטָרְפוֹת. רַבִּי יִשְׁמָעֵאל אוֹמֵר, הַנּוֹצָה מִצְטָרֶפֶת. הַחַרְטוֹם וְהַצִּפָּרְנַיִם מִטַּמְּאִין וּמְטַמְּאִין וּמִצְטָרְפִים. רַבִּי יוֹסֵי אוֹמֵר, אַף רָאשֵׁי אֲגַפַּיִם וְרֹאשׁ הַזָּנָב מִצְטָרְפִים, שֶׁכֵּן מַנִּיחִים בַּפְּטוּמוֹת: