Certain birds enable people to comprehend the inexplicable because they embody contrasts and resolve oppositions, and some birds have particular attributes that make them especially adept at expressing these symbolic meanings. This analysis focuses on two bird families that are central to the social organization of many societies in the Americas for their relationship to both life and death, and considers how these birds are able to mediate cultural oppositions expressed through the myths, rituals, art, and architecture portrayed in both ancient and contemporary cultures. Having features associated with both life and death, hummingbirds and vultures embody a duality that enables them to fly symbolically higher into the heavens and lower into the underworld than many other birds. Ethnographic examples from Mexico, Costa Rica, and Peru are used to illustrate the ways these particular birds are seen as transforming life and death by leading to a more profound understanding of reality as an ongoing cycle of rebirth and renewal.