Ravens Versus Crows

When I speak of ravens or crows to people, often they want to know what difference exists between the two. Usually, they know of a size difference, but want to know how else to differentiate the two. Therfore below, are listed some of the defining physical differences, social/behavioral deffences, as well as some expert thoughts and perceptions on the American crow (Corvus brachyrhynchos) and common raven (Corvus corax).

"To get at the mind of a crow is a great challenge, but to get in the mind of a raven, as I found in living with one for a year, is an even greater one. Ravens are, to enthusiasts like myself, at the top of the avian pyramid in mental attributes."

-L. Kilham from "The American Crow and Common Raven"

"Given the tendency of corvids to be large, intelligent, adaptable, ground-foraging birds independent of trees, it is probably only a slight exaggeration to say that the raven (C. corax) is the ultimate Corvid. If so, it is also at the top of the most species-rich and rapidly evolving line of the birds. Is is the ne plus ultra of up-and-comming birds."

-Bernd Heinriech from "Ravens in Winter"

Physical Differences: Crows average around 17 inches long, and ravens about 24-27.

A raven weighs about four times that of a crow.
Crows have a wing span around 2.5 ft., and ravens about 3.5-4 ft.

A raven's wing sometimes makes a prominent "swish, swish" sound, while a crow's wingbeat is usually silient.

Ravens have pointed wings, while crows have a more blunt and splayed wing tip.
Crows have a fan-shaped tail (squared-off), while raven tails are long and wege-shaped.
Besides having a bigger, more powerful bill, a raven's bill is curved, while a crow has a more-or-less flat bill. Additionally, atop a raven's bill is a tuft of hairs absent on crows.

As a result of being larger and more powerful, ravens are the more efficient predator. (Predation is a very small percentage of crow and raven diets.)

Range/adaptive skills: While both crows and ravens have experienced persecution in the eastern United States, the crow managed to adapt and increase in numbers, while the ravens greatly declined (although recently the raven is making a comeback in places like Maryland). B.Heinriech says this may be due, in part, to the raven's propensity to reuse nest sites, which are easy to find and destroy. Additionally, ravens, utilizing carrion more than crows, probably disappeared along with the wolves and buffalo. Poisons to rid wolves from the landscape also contributed. Agriculture, however, increased in the east, increasing the crow's food base and ability to increase in numbers.

Crows are more at home in the urban landscape, given their ability to be more socially inclined than ravens.

Diet: While both are commited to being vociferous omnivores, ravens are drawn to carrion (especially sheep), while crows may be less picky.

Ravens probably find food faster in the wild, considering anecdotes from tappers about how fast ravens could find the carrion in their traps.

Vocalizations: For the sake of basic reference, a crow's call is a "caw" and a raven's is a low and slow croak.

Crows exhibit at least two dozen differnt calls, while ravens can express themselves with 20-100's of different vocalizations, depending on the expert cited.

Interspecies relations/behavior: L.Kilham, from The American Crow and the Common Raven (1989)wrote that he observed ravens repeatedly chasing crows from a feeding station, always resulting in the crow dropping the cache. This would unnerve th crows to no-end; causing them to gather at a roost and caw vehemently, yet they still repeated the cycle.

Jollie (1976) stated that ravens seldomly attack crows because crows can outmaneuver and outclimb them. However, Kilham observed the opposite to be true at the New Hampshire farm study site, where the ravens outmaneuvered the crows in the forest and well as in the open.
Kilham observed crows doing fewer jump-backs when approaching food. Ravens are more cautious or less audacious. (Jump-backs are reactions that crows and ravens do in times of caution, possibly testing for a reaction from the possible food source.) Furthermore, Conner (1975) noted that ravens would not approach a landfill until there were at least four crows present. After awhile if no crows were present, they would use their own lookouts. Several accounts exist of ravens using crows as their sentinels.
While subjective, limited, and hard to extrapolate from, Kilham's hand-raised raven liked being indoors much more than the hand-raised crow. Additionally, h noted that the raven liked low place (chairs, counters) while the crow liked higher spots such such as atop a door.
Ravens at times will fly wing-to-wing with their mate, with the females just below the males.

Science: Bernd Heinrich, an academic field biologist, spent four consecutive winters at a cabin in Maine watching ravens at feed stations, attempting to fill-in a piece of the puzzle to a question concerning an obvious paradox he witnessed with the ravens. The question that pervaded his mind occured while he was doing some work on bees: He had observed ravens at a carcass "sharing" the prized meat and wondered why a pair of ravens would not defend such a prize at a time when meat supply was scarce. The logical, and proper evolutionary response would seem contrary, with the discovers indignantly fending-off other prospective takers.

After his four winters of observation and eperimentation, he learned that the raven's (unmated juveniles) possibly "recruit" others to a food source because, by sharing with others it gains "friends," from which it may gain a mate from in the future due to its foraging abilities. While mated pairs are more-or-less anchored to their localized nesting area; low status juveniles are left to form wondering unmated "gangs." Thus, mated pairs would not benifit from "recruiting" others to a food source, and likewise, juveniles are careful not to tip-off dominant mated adults.

More information can be obtained from Ravens in Winter, by Bernd Heinrich (1989).

Email: tkarki@hotmail.com