The name "crow" is used for an entire family of birds, Corvidae, that includes the raven species. To put it simply, all ravens are crows; but crows can also be jays, magpies, or other birds. The terms "crow" and "raven" are actually very general, and can be used to refer to a number of different related birds in the Corvus genus. In the United States, most people use these terms to refer to the American Crow (Corvus brachyrhynchos) and the Common Raven (Corvus corax). While these black birds have many similarities, there are differences in their appearance, noises, and habitat.
Differences in Size
The most noticeable difference between a crow and a raven is size; in most cases, the largest black birds in this genus are known as ravens. Common Ravens are noticeably larger than American Crows, for example. Ravens average 25 inches tall (64 cm) with a 4 foot (122 cm) wing span, about the size of a hawk, while crows are around 18 inches (46 cm) tall and their wings span 3 feet (91 cm), similar to a dove.
These two types of birds can also have some differences in their feathers. Both are iridescent black, although a crow's older feathers are often lighter. A raven's feathers shine with a blue or purple tint when the sun hits them, while an American Crow may look purple with green-tinted wings. Crows can fluff their feathers into a mane to show off, while a raven's individual feathers are larger and pointier, giving the throat a shaggy appearance.
Crows and ravens also look different in flight. Ravens tend to soar in the air, and sometimes do somersaults in flight. Their wings are longer and thinner, and the primaries — the main flight feathers on the wings — are also longer and have more space between them. The birds' tails also look different when spread; a crow's tail curves evenly like a seashell, while the tail of a raven meets at a triangular point.
The beak of a crow might look slightly thicker than that of a raven, but the raven's bill tends to be larger in general. It also tends to curve close to the end, while the beak of the crow curves down about half to two-thirds of the way along it.
One of the most interesting differences between the two birds is in their vocalizations. As anyone who has tried to dissuade birds from hanging around by putting up a scarecrow knows, the caws of a crow are often considered annoying and repetitive. A raven's voice is more varied, however, and it's able to imitate other birds and animals. Its most distinctive noise is a deep, croaking sound, which is often considered more musical than the call of the crow.
Habitat and Other Differences
Crows are tolerant of noisy, populated areas with people and other animals, which gives them their reputation for harassing the cornfields of farmers, since they like scavenging seeds, fruits, and vegetables in groups. Ravens like privacy in their solitary hunt for insects, fruits, and carrion, so they're more likely to be found in remote woods, meadows, and hills. They adapt well to many different environments, however, and are found even in Arctic areas.
The lifespans of the two birds do vary; a raven often lives 30 years, while a crow only has an average of eight years, though they can live longer in captivity. Crows are also very susceptible to the West Nile virus, and many birds have died from this disease since 1999.
There are at least 9 different species called ravens and 30 species with the name crow, plus a number of sub-species of each. In addition, other species within the Corvus genus include the Western Jackdaw, the Daurian Jackdaw, and the Rook, all three of which are also solid black birds. The wider Carvidae family includes a wider range of sizes and colors, including treepies, choughs, magpies, and jays.