Which Birds Are Kosher? The Halachic Rules, Traditions, and the Mystery of Turkey

Throughout history, whenever a new species of bird was discovered, or when birds were imported from one continent to another, the question always arose: Is this bird kosher and permitted to be served on the tables of the Jewish people, or is it among the impure birds?

Halachic Signs of a Kosher Bird

By strict halachic definition, it is technically possible to determine whether a bird is kosher based on three signs of purity, as written in the Shulchan Aruch (Yoreh De’ah 82:2): “There are three signs of purity: an extra toe, a crop, and a gizzard whose inner lining can be peeled by hand.”

However, the Jewish people have adopted the custom not to rely solely on these signs, and not to eat any bird unless we have a mesorah — a received tradition from our ancestors — that this species is kosher and has historically been eaten. This ruling is mentioned in the Rema (Yoreh De’ah 82:3).

The Source for Requiring a Mesorah

The origin of this custom appears in Rashi’s commentary (Chullin 62b). He writes that during the era of the Talmudic sages, a certain bird was eaten because it showed all the halachic signs of a kosher species. Yet later, they observed that the bird exhibited behavior typical of non-kosher birds — it tore its prey, a sign of a predatory, non-kosher bird.

It then became clear that their identification of the kosher signs had been mistaken. From that point onward, the accepted practice became: “We do not eat any bird unless we have a clear mesorah that our ancestors consumed it.”

Therefore, whenever Torah authorities needed to rule about a bird previously unknown to Jewish communities, they could not rely on signs alone. They had to determine:

• whether the new bird was truly the same species as another bird for which a mesorah existed,

• or whether it was a different species altogether, and thus — lacking a mesorah — forbidden.

Not All Mesorahs Are Equal

Even when a mesorah existed, the great rabbis were extremely precise about its validity.

About 100 years ago, a new variety of geese arrived in Warsaw from deep within Russia. Although Jews in their place of origin had apparently eaten them, the Avnei Nezer (Responsa Yoreh De’ah 75) ruled that such a mesorah could not be relied upon. This is because a mesorah is trustworthy only in a place where Torah scholars live and supervise halachic practice. A custom from a remote region without learned oversight was insufficient.

Is There a Mesorah on Turkey?

The turkey was imported into Europe from the American continent. Naturally, it arrived without any mesorah, as no Jewish community existed in America at that time.

Halachic sources note that it is not known exactly why or how the custom permitting turkey spread so widely. Nevertheless, since this has become the accepted reality, many authorities examined whether this practice is halachically justified.

The Netziv of Volozhin (Responsa Meshiv Davar, vol. 2, siman 22) explains:

• The custom not to eat birds without a mesorah applies to new, unfamiliar species, regarding which we have no tradition.

• But we did not accept upon ourselves to suddenly prohibit birds that have already become widely eaten, simply because we lack an explicit mesorah.

In other words: ​Turkey is permitted not because we have an ancient mesorah, but because the Jewish people already adopted it as a kosher species — and halacha recognizes that accepted, established practice.