The Crow and the Raven explained simply

A Crow became very jealous of a Raven, because the latter was regarded by men as a bird of omen which foretold the future, and was accordingly held in great respect by them. She was very anxious to get the same sort of reputation herself; and, one day, seeing some travellers approaching, she flew on to a branch of a tree at the roadside and cawed as loud as she could. The travellers were in some dismay at the sound, for they feared it might be a bad omen; till one of them, spying the Crow, said to his companions, "It's all right, my friends, we can go on without fear, for it's only a crow and that means nothing." Those who pretend to be something they are not only make themselves ridiculous.