With all the confusion, what is the normative halacha? SomeRishonim,such as the Ramban (Chullin 62) who describes examining many birdsto identify the kosher traits, were willing to trust their understandingof the Talmud and to rely on the physical characteristics. TheShulchanAruch (YD 82:3) narrowed the use of physical signs and required a prioriknowledge that the bird is not adores. TheShulchan Aruchalso provided some means, to be discussed below, of ascertaining that abird is not adores.
Rashi (Chullin 62a), based on the incident of the tarnugulsad'agma in which people ate a non-kosher bird as a consequence of applyingphysical characteristics 19as a criterion, opines that we can never be sure that a bird is not adoresand hence rules that birds may be eaten only if there is amesorah- a tradition attesting to the acceptability of this particular species.
The Ramo (YD 82:3), the principal authority for all Ashkenazic lands,followed the lead of Rashi and theLevush and ruled that the onlyapplicable principle as far as he is concerned is that "no bird shouldbe eaten unless there is amesorah that it is a kosher species."20
This ruling of the Ramo, 22that there is an absolute requirement for amesorah motivates thequestion regarding turkey, a New World species, and will be the launchingplatform for what follows. If "no bird should be eaten in the absence ofamesorah" how is it possible for a New World species to be kosher?