Introduction

This large, black, majestic bird is geographically and ecologically one of the most widespread naturally occurring birds in the world. It is distributed throughout major portions of North America, Europe, Asia, and North Africa, and in all terrestrial biomes except tropical rain forests. Historically in North America, it lived on the Great Plains in association with American bison (Bison bison) and wolves (Canis lupus). It still lives in wilderness areas throughout much of the continent, is reestablishing its former distribution in forests of the east, and is even moving into urban areas in parts of its range—adapting to human presence much as it also associates with other top carnivores. In some parts of its range, ravens are considered pests whose populations are rapidly expanding, and programs have been implemented to reduce population sizes. In other parts of its range, populations have declined so drastically that reintroduction programs have been implemented.

The largest-bodied of all passerines, this raven is widely known for being a scavenger on animal carcasses and human garbage. It is also a predator, hunting rodents in fields, pulling nestlings out of nests, and taking food from conspecifics and heterospecifics. Its diet includes large numbers of arthropods, including scorpions and grasshoppers, and sometimes large amounts of seeds and grains.

Often considered a pest because individuals eat agricultural products (e.g., peck eyes from newborn lambs) and damage human-made objects (e.g., peel identification labels off toxic waste drums), the Common Raven has also been implicated as a causative factor in the declines of several threatened and endangered species including desert tortoise (Gopherus agassizii), California Condor (Gymnogyps californianus), Marbled Murrelet (Brachyramphus marmoratus), and Least Tern (Sterna antillarum).

This species has long been a part of the folklore of many cultures. Native Americans of the Northwest revere ravens as being the creator of earth, moon, sun, and stars, but also regard it a trickster and cheater. Poets and authors of Western cultures have often used the raven to symbolize death, danger, and wisdom. It is difficult to imagine any other bird being associated with so much myth, mystery, and misinformation. Nonetheless, despite more than 1,400 research reports and articles on this bird in the scientific literature, there are many gaps in our expanding knowledge of this fascinating species.