Bernard Malamud's short story The JewBird is indeed an allegory about Jewish self-nature, specifically, the negative perception some Jewish people have towards their less-fortunate, less-assimilated brethren. Anti-semitism has been a scourge of human existence for thousands of years, predating even the life of Jesus. Hopes among some Jews that assimilation into their broader environment would eliminate anti-semitism have repeatedly proven misguided, but such hopes live eternal. In Malamud's story, a black crow, having fled its land of origin -- presumably Eastern Europe -- to escape virulent and violent anti-semitism, heads for the center of European Jewish emigration, New York. Having landed at the residence of an assimilated American Jewish family, the Cohens, the bird believes it has found safety and acceptance. Explaining its sudden arrival, the crow declares that it has come to America to escape yet another violent attack on the Jewish population of its European home, stating, “Gevalt, a pogrom!” 

"Pogroms" are the word given to officially-sanctioned and unofficial but tacitly-approved violent attacks on Jews by Eastern European Christian and Middle Eastern Muslim majorities. The crow, identifying itself further as a "Jewbird," has fled continued pogroms. The Cohens, a human family, are mystified by this new arrival's statement, with Mrs. Cohen, Edie, asking how or why a bird could be the target of such an attack:

 “What kind of anti-Semites bother a bird?” Edie asked. 
       “Any kind,” said the bird, “also including eagles, vultures, and hawks. And once in a while some crows will take your eyes out.” 
       “But aren’t you a crow?”

With this exchange, Malamud has established the setting for the allegory he will now convey. As the bird assumes residence with the Cohen family, it increasingly finds itself subject to criticisms and treatment generally afforded a "lesser" being by those who constitute a majority, if only in a small apartment. The irony, of course, is that the Cohens themselves are Jewish, yet look upon this immigrant from 'the old country' as culturally inferior and worthy of their contempt. Malamud's story, therefore, is an allegory about what is often termed "Jewish self-hatred." While this phenomenon exists among many immigrant communities, it is particularly note-worthy for its existence among a population historically condemned and attacked solely for its faith.