The Mishna teaches:
One may insulate a pot of hot food on eve in clothing, in produce, in doves’ wings, in a carpenter’s wood-shavings, and in the chaff of fine flax. Rabbi Yehuda prohibits doing so when it is fine, and permits doing so when it is coarse.
The Gemara asks:
And why did they call Elisha Man of Wings? Because on one occasion the evil kingdom of Rome issued a decree against Israel that, as punishment, they would pierce the brain of anyone who dons phylacteries. Nevertheless, Elisha would don them and defiantly go out to the marketplace. One day, an official who was appointed to enforce the decree saw him; Elishah ran away from him, and the official ran after him. When the official reached him, Elisha removed the phylacteries from his head and held them in his hand. The officer asked him: What is that in your hand? Elisha said to him: It is merely a dove’s wings. A miracle was performed: He opened his hand, and, indeed, it was found to be a dove’s wings. Therefore, in commemoration of this miracle, they would call him Elisha, Man of Wings.
The Gemara asks:
And what is different about doves’ wings from those of other birds that led Elisha to say that he had doves’ wings in his hand? The Gemara answers: Because the congregation of Israel is likened to a dove, as it is stated: “You shall shine as the wings of a dove covered with silver and her pinions with yellow gold” (Tehillim 68:14). Just as this dove, only its wings protect it and it has no other means of protection, so too the Jewish people, only mitzvot protect them.
The simple explanation to this story is that a dove has no means of protection other than its ability to make use of its wings and fly away from its enemies. This stands in contrast with other birds which have other means to defend themselves from danger.