Mind of the Raven: Investigations and Adventures With Wolf-Birds (26 page)

An intriguing question is whether or not ravens can learn arbitrary sounds and then associate meaning to them. For example, babies may at first babble and make sounds like “mama” or “dada” that they only later associate with the appropriate subjects. Darwin, the raven that Duane Callahan is currently training for wilderness rescue work in California, gives hints of recognizing the meaning of sounds he makes, perhaps because he gets rewarded with certain coincidental associations. For example, he has learned what the words “Want to go outside?” mean, because Duane always uses them before he takes him out of the house for his free flight. He may also have learned “Duane, Duane” from Susan and Duane’s brother Charles. Now Darwin says, “Duane, Duane, want to go outside?” when he wants to go out. He is, in effect, perhaps asking to go for a walk. Darwin also perfectly mimics Charles’s raucous laugh. Sometimes when the telephone rings and Duane answers, “No, Charles isn’t here right now,” Darwin will erupt in the background with “a perfect rendition of Charles’s laugh.” Is it sheer coincidence? Does the raven hear “Charles,” and knowing who that is, then think of his laugh?

The ravens’ vocalizations invite comparison with our language, and with that comparison in mind I was especially interested in the development of language in my son. Eliot’s first sounds were cries of emotion, signifying discomfort, surprise, contentment, or anger. Parents are able to decipher at least some meaning from context, much as
I can often learn meaning from a raven’s calls from context. Eliot’s other early vocalizations were sounds of recognition. On seeing a cat, a dog, a car, or a turtle, or almost anything else that surprised him, he said, “Da, da, da—” and the number of times he repeated it was variable, depending on his surprise. I suspect that like the raven’s
rap-rap-rap
calls, his vocalizations meant, “I see, and I’m interested and surprised.” The next stage in vocal development concerns specificity. For example, ravens’ various levels of surprise and alarm are expressed at different predators or potential predators, although there are no raven words for them. If specific calls have meanings, they can be correctly interpreted only by those other ravens who regularly associate with that particular individual and thus know what sound is associated with what object. It was similar with Eliot. At age twelve months, for example, wetness or anything liquid was “juice.” He divided the animal world into “dog” (all furry animals), “turtle” (reptiles and beetles), and “fish” (pisces of all the various orders as well as dolphins). “Dada” was dad, and curiously, also some men and any ape. In time, he would distinguish ever finer details, and the sounds he made would have specific meaning to an ever-greater circle of others beyond parents, relatives, and associates.

After Goliath and the other three ravens of his group settled into their roost to sleep at night (when less than a half year old), I often opened my bedroom window into their shed and talked to them as one might to a baby. They always answered with soft, low murmurs—
km, mm
. When the murmurs were very low, soft and long and almost whispered, I learned the birds were at ease, as could also be seen from their relaxed postures. The calls seemed to be contact calls meaning, “I hear you. Everything is fine.” The young gave the same calls with a slightly upward inflection when we explored together in the woods and lost visual contact with each other. I presumed in that context they meant, “Where are you?” because when I answered the birds, they responded without that inflection, and I knew they had heard me and were still in contact. If they were being attacked by a predator, I’m certain I would have known it from their calls as well. I’m also certain nobody else would who did not know the birds.

Their intimate calls at the evening roost were usually almost whispers when we were very close together. I was reassured by their whispers and I reassured them. After our chat was finished, I sometimes heard a muffled shake of feathers, little zipping sounds of pinions drawn through bills, rapid dull scratching of toenails on the back of a head, and hollow-sounding footsteps as one shifted along its wooden perch. After I closed the window, I occasionally still heard a soft cough or a stirring on a branch. These sounds had meaning to me, because they said something about the behavior of the birds on the sleeping roost.

As my ravens got older and more independent, they chatted less with me. Instead, they woke me at the first sign of dawn with raucous calling. Perching on the windowsill, they pointedly peered in and made mostly bouts of
rap-rap-rap
calls and also deep, penetrating, long rasping caws. Both calls were otherwise given when raven intruders came near. Here in a different context, they had an entirely different meaning. My ravens wanted my attention and food. They got it, and thus I reinforced their specific vocal behavior. When they were hungry, they also gave long, drawn-out, high-pitched calls, which I call their “beg” or “yell,” and they stopped after I fed them.

Still other calls draw attention and probably say, “Here I am,” but from a very long distance. These are probably territorial calls because they can be heard for miles, and are usually answered by neighbors but never attract them. There are several of these loud, long, penetrating calls that are used equally by both sexes. I suspect they are less to get attention, as such, as to say, “This area is claimed.” When these calls are directed at ravens within visible contact, the callers erect their “ears,” flare their shoulders, and puff out their throat hackles. The macho display is omitted when the same calls are directed to me. I presume that their intent is to get my attention, because my tame birds stop giving them after I open the window and greet them.

Numerous other raven calls are given in what appear to be specific circumstances, when one emotion should predominate and be expressed as casually and without conscious intention as eagerly jumping off a perch at dawn. For example, one might expect alarm when a human or
other predator approaches the nest. Instead, many different kinds of calls may be given, and the mix of calls varies from one pair to another. A seemingly much more alarming situation, such as capture, never evokes a sound from them. I suspect that calling when they are vulnerable and helpless could attract predators, not helpers, and so silence is then golden. There are numerous nuances of comfort sounds, yet recently captured wild birds give no “shouts of joy” on release from one’s hand. In that case, calling to reveal emotion would serve no purpose because there is no potential listener that could benefit them for giving the call. However, that’s an oversimplification—ravens often vocalize without any apparent listener near.

Raven Number 34 was an example. He was one of twenty-two wild-caught birds I had released after I had kept them in the aviary for over a year. After these birds left, Number 34 remained, perching alternately on top of the aviary, on a beech to the left of it, or on a big red maple to the right of it. For hours, he sang. His song was so uplifting and exuberant to my ears that I got out my tape recorder and started recording. I sat down less than fifteen feet from him and he paid me no attention. He was gurgling, chortling, yelling, trilling, bill-snapping,
quorking
, and making sounds like water rattling pebbles. The bird made no female knocking sounds, so I speculated that it was probably a male, but I could not be sure.

As he sang, he raised his head high, often turning and gazing in all directions, alternately preening, stretching, picking at twigs, and gulping bills full of snow. I talked to him, telling him how beautiful his raven song was—that it was the most beautiful thing I’d ever heard. He didn’t know precisely what I said, but I venture he got my message; he would have responded differently if I had made sharp, rapid yells toward him. As I had intended, he showed me not the slightest visible attention. He continued to sing, rising to another loud, rasping crescendo, then fading into a series of soft chuckles and gurgling sounds. A second recent releasee was engaged in a similar monologue far down the hill in the nearby woods, where it was also all by itself. I had never once heard these raven songs where there was a large audience, at a carcass, for example.

An anthropomorphic biased view could be that the birds sang because they were overjoyed to be released from the cage. If it had been freedom, then they all should have started to sing when first let loose. They knew they were free, because they perched in the woods all around, then returned into the cage, onto it, and all around it before dispersing. None of the twenty-two had, to my knowledge, sung at all during the whole previous year while they were in the crowd. On another occasion, I released three birds out of four, and the bird
remaining
alone in the cage was the one that erupted in song. I concluded that they started to sing because the others were gone. As previously mentioned, dominant birds may totally silence others of their own sex.

Their expressions of anger are usually directed toward another raven and hence they are a potentially far more immediately useful signal than expressions of joy for self. The raven’s anger is expressed most palpably in those individuals that know their enemies and are brave and knowledgeable enough to defend the nest. When a human or presumably other predators approaches their nest, these birds violently hammer branches, tear off and toss twigs and cones, and give deep, long rasping caws that convey that the caller is powerful and serious. A raccoon trying to raid the nest would read this display correctly, and a human may do so as well.

One out of a myriad of other examples of ravens expressing anger occurred in the aviary complex where the wild-caught birds had become thoroughly used to my bringing them food. When I set food down, they always flew right over and started feeding. One day, I happened to be blocking the door to the side aviary with C48 inside, who wanted to get out by me to get to the food. He came up to me, looked me in the eye, and erupted in the same long, deep rasping alarm or anger calls that greet me when I intrude at nests with young. This demonstration would have been unthinkable earlier in the year, when he was still fearful of me and always yielded. Fright always won out over all other considerations. This time, he did not fear me and he dared to show his emotions. Given the circumstances, his message was clear to me: “Get out of the way—I want to get past you to the food.” Without the context and my personal experiences with ravens, his
vocalizations would have been meaningless. They would have contained no message.

He would not have given his message if he did not feel he had a chance of making me yield. He had in effect talked with me, because his message was directed at me only. I heard, understood, and stepped aside. He immediately slipped by.

Alert and confident
.

Body language is also extremely important to ravens. Obviously, actions speak louder than words with them. Contrary to numerous accounts in the literature, I have never heard a raven give an alarm call when I have come near a feeding crowd. If only one bird of the group sees me and flies up in alarm, the others also fly up almost instantaneously. I have on several occasions been hidden from the feeding crowd when a bird that is flying overhead sees me and changes the rhythm of its wing-beats, usually in rapid backpedaling of its wings. Without one vocalization being given, the crowd instantly flies up and scatters, even though they may have been feeding out of my view over the rise of a hill.

Since ravens are much smarter than insects, they don’t need a long song and dance, as do honeybees, to alert them when one of their fellows has found food. Information is contained in simple action. Suppose a group of four to five ravens who know where there is food eagerly leave the roost thirty minutes before sunrise. Since all the birds who know where food is go first of all to feed in the early morning, these birds may realize that something is up when others leave so eagerly and so early. Not knowing where food is, the hungry birds follow those who demonstrate strong motivation.

My speculation is not without data. I spent one winter getting up every day hours before dawn to climb tall spruce trees near baits I had put out. Aside from the pure enjoyment of climbing snowy trees in
the dark at subzero temperatures, I did it to count birds. I found that the
first
big crowds at a carcass always arrived before light. On succeeding days the birds came increasingly later and in smaller groups, even as individuals and pairs. Once feeding had begun, birds knew where the food was. From then on, they did not have to follow any other bird, and they did not have to leave the roost long before dawn when the first birds left. They were free to come on their own at any time. Some would say the ravens were not conveying information, and that this was information-parasitism instead. That implies that one benefited at the expense of the other. In the case of the ravens described above, both followed and follower birds benefited; they both got to feed by overcoming territorial defenders and/or reducing their fear of the food. So it was a communication, even if nonvocal.