Owls Aren't Wise and Bats Aren't Blind (21 page)

Northern raven
;
American (common) crow

13

An Entertaining Pair: The Crow and the Raven

MYTHS

A crow can imitate a human voice better if its tongue is split.

Ravens are a great threat to calves, lambs, and other domestic livestock.

Crows can count up to a certain number.

THE AMERICAN CROW
(CORVUS BRACHYRHYNCHOS)
AND ITS LARGER RELATIVE, THE RAVEN
(CORVUS CORAX),
ARE LARGELY IGNORED AND FREQUENTLY DESPISED. That’s very much our loss, for few birds will reward study and observation as much as these intriguing, astonishing, and sometimes very comical birds.

Of the two, the American crow is by far the more common and widespread. Three other species of crows, incidentally, are also found in the United States, though in much smaller numbers: the fish crow
(Corvus ossifragus)
and the Northwestern crow
(Corvus caurinus)
aren’t nearly as widely distributed as the American crow, and the Mexican crow
(Corvus imparatus)
barely enters the United States in southern Texas.

The American crow inhabits most of the lower forty-eight states, as well as Canada north to the latitude of the junction of James Bay and Hudson Bay. Its larger relative, the common raven, is more northerly. It inhabits virtually all of Canada and Alaska, including their far Arctic reaches; New England; parts of a few other northern states; the Appalachian Mountains; and a broad swath from the Rocky Mountains to the West Coast and south into Mexico. It also appears that the raven is steadily increasing its range.

Telling crows and ravens apart where their ranges overlap can be difficult and may seem like a daunting task to the uninitiated. Size isn’t a very reliable criterion, despite occasional wildly exaggerated accounts of the raven’s size. A recent news item, for instance, called ravens “huge birds” and claimed that they’re three times the size of crows. If that were true, the raven would indeed be huge—nearly four and a half feet long, with a wingspan of well over six feet!

Although the raven is somewhat larger than the crow, the differential isn’t great: a big crow and a small raven are nearly identical in size. Despite the fact that size alone can’t always distinguish between crows and ravens, especially at a distance, observers needn’t despair: there are at least four or five other characteristics that singly, or especially in combination, will usually differentiate the two quite easily.

The tail, if it can be seen clearly at close range or silhouetted overhead, is one of the best identifying features. The crow’s tail is square across its outer end, whereas the raven’s is distinctly wedge-shaped at the rear. The beak is also useful for identification at short range, for the raven’s beak is much heavier and more powerful than the crow’s.

A third means of distinguishing crows from ravens is their calls. Although the two are closely related, their voices are much different: both have a very large repertoire of calls, some of them somewhat similar, but their most common and widely heard sounds are quite different and very useful in distinguishing between the two.

The crow’s basic call is the familiar caw, often repeated over and over, but with different inflections and varying degrees of intensity, depending on the type of message that the crow wishes to convey. Alarm calls when an approaching human is sighted, for example, or the calls when crows are mobbing a hawk or owl, are far more intense and frantic than the caws that routinely go back and forth between crows. Crows also use numerous other calls, such as rattles, clicks, and various other sounds. However, these are heard far less often than the ubiquitous caw, at least partially because they don’t carry as far.

Ravens, on the other hand, commonly use a variety of distinctive sounds. A guttural croak, a loud
rrrawwkk,
and a
quork
are among the most common. However, the most unusual raven call is a loud, ringing
goink
that sounds to me much like someone pounding on a huge wooden xylophone or gong, although others think it sounds more metallic. Ravens also gurgle, make noises which, at a distance, sound like people talking or laughing, and produce a variety of other sounds. It also appears that there are regional variations in raven calls, sometimes described as dialects.

One time-honored myth holds that a crow can be taught to talk if its tongue is split. This is nonsense. Crows are mimics, and have some capacity for imitating the human voice, but it falls far short of that displayed by birds such as parrots and mynahs, and a split tongue is of no help whatsoever.

Ravens do better in this respect, although that seems to depend a great deal on the individual raven and its inclination to imitate the human voice. For example, one scientist thought that it would be fun to teach a raven to say “Nevermore,” as did the raven in Edgar Allan Poe’s famous poem. The scientist succeeded—but it took him six years in the process!

On the other hand, there are credible reports of ravens performing amazing feats of mimicry. Scientist Bernd Heinrich has done outstanding work with ravens over the past fifteen years and contributed enormously to our understanding of these fascinating birds. In his book
Mind of the Raven,
Heinrich cites reliable sources for such things as a raven imitating radio static, a motorcycle being revved up, the sound of flushing urinals, and—most astonishing—an imitation of a demolition expert saying “three, two, one,” followed by a reasonable facsimile of a dynamite explosion.

Although ravens clearly have the ability to mimic many things, including the human voice, their performance seems to depend on the
desire
to do so. Therefore, anyone wanting a bird that he or she can teach to say various words would probably do better to acquire a mynah or parrot.

Flight is a fourth means of telling crows and ravens apart, for it’s perhaps in flight that the greatest difference between the two species is displayed. Although crows are excellent fliers, their flight is mostly a steady, uninspired, and laborious-appearing flopping. That doesn’t mean that they can’t perform more intricate maneuvers, but these are normally limited to special circumstances, such as landing in a high wind or mobbing a hawk or owl. Given their ability to roll, dive, and glide, their rather prosaic flight under most circumstances may be more a matter of choice than of ability.

Ravens, on the other hand, are magnificent fliers that seem to revel in displaying their talent. They routinely soar and glide like hawks, but they far transcend even that exalted level of flight. Often they engage in aerobatics reminiscent of mock dogfights between exhibition airplanes. In the process they perform barrel rolls, tumble in a variety of intricate moves, and even drop objects and catch them again while in flight.

At other times they display enormous precision by locking talons in flight, with one raven bottom side up beneath the other. In what’s perhaps their most spectacular maneuver, they fold their wings and plummet like a sky-diver for substantial distances before suddenly “opening their chute” and whipping into yet another display of aerial prowess. These spectacular aerobatics never fail to evoke a sense of wonder and admiration for these magnificent fliers.

The raven’s powerful wing beats can yield still another clue to its identity. A crow flying overhead makes little sound with its wings, even at rather low altitude, while a raven at the same height is clearly audible. Countless times when I’ve been in the woods, a distinctive
whuffwhuffwhuffwhuff
has made me look up to see a raven passing overhead.

The corvids—crows, ravens, jays, and magpies—are generally thought to be quite intelligent, but scientific evidence has been hard to come by. Bernd Heinrich, however, has done numerous experiments with ravens and given them the equivalent of avian IQ tests. In his most imaginative experiment, Heinrich tied food to one end of a string and attached the other end to a raven’s perch. To reach the food, the raven had to perform a complex series of tasks: pull the string up with its beak, use a foot to hold the loop of string firmly against the perch, and repeat the operation several times until the food was finally raised within reach of its beak.

Several of his captive ravens were able to solve this problem on the first try and subsequently repeat the procedure. Others took longer, but were still able to come up with the same solution. This is especially impressive because Heinrich had taken pains to ensure that these ravens had never so much as seen a piece of string prior to the experiment. In contrast to the ravens, Heinrich’s two crows (an admittedly small sample) never did figure out how to get at the dangling food.

Does this test prove that ravens are intelligent? The notion of intelligence is, at best, a hotly debated one. Respected scientists have widely divergent views on the subject, and a grand academic brawl is almost certain to ensue if anyone has the temerity to declare that this action or that test is proof of intelligence—or even to define intelligence, for that matter. And if scientists can’t even agree on a definition of intelligence, it’s virtually impossible for them to agree on a means of determining how much of it a creature possesses.

Heinrich is a cautious scientist, understandably reluctant to place his head firmly on the scientific chopping block by declaring that ravens are intelligent. However, he clearly leans in that direction when he says that he believes they experience some level of consciousness that they use in making decisions: “Whether that is ‘intelligence’ is subjective; but according to most people it is.” I certainly concur in that judgment.

Crows are also widely regarded as intelligent, and perhaps they are, again depending on one’s definition. However, one of the supposed measures of crow intelligence—the ability to count the number of hunters in a group— is highly suspect. According to this oft-repeated tale, if crows see, for example, four hunters go into a patch of woods, and then see only three depart, they know that the woods are unsafe because a hunter remains there. Also according to the tale, above a given number the crows can no longer tell whether or not all the hunters exit from the woods.

There might be a grain of truth in this: crows could conceivably recognize instinctively that two hunters emerging from the woods don’t look like as many as three or four. However, such incidents are anecdotal, subject to a great deal of exaggeration, and, even if true, contain so many variables as to make them totally speculative and unreliable. Beyond that, using such an incident as the basis for saying that crows can count is straining credibility to the breaking point.

Crows are extremely social birds, and during the winter months they often gather in huge roosts that may harbor close to a million members! In the daytime they travel as much as twenty miles from these roosts in order to find food. Crows in large numbers can be a serious threat to crops, and need to be controlled under some circumstances.

As many farmers and gardeners know to their sorrow, crows especially like sprouting corn seeds. This has put the crow into marked disfavor with many, and has led to the use of various devices—scarecrows and imitation great horned owls among them—in an attempt (usually unsuccessful) to keep crows away during the critical period while the seeds are sprouting. However, on an overall basis, crows are regarded as beneficial because of the vast quantities of destructive insects, such as grasshoppers and cutworms, that they consume.