Mind of the Raven: Investigations and Adventures With Wolf-Birds (23 page)

Others have written to me about seeing a white raven flying in a flock with others. One young emaciated white raven was found in New Brunswick, Canada, and ended up in an animal rehabilitation center. Mary Majka, the raven’s keeper, wrote, “Albie is tremendously shy and scared of his own shadow. We’ve had regular ravens here before, and they were very intelligent, inquisitive, bold individuals. But this bird, although he’s been with us for two years, still displays the same shy behavior.” I wasn’t surprised that Albie had idiosyncratic behavior. Most do, once you get to identify them and to know them.

I was sent a photograph of a chocolate brown raven that an Alaska newspaper article described as “the first off-color raven in Anchorage,” although a dark silvery metallic one had been seen there in the 1970s. The bird is “very noticeable. When the sun hits him he’s almost like a golden raven,” Alaska raven biologist Rick Sinnett wrote. “This bird seems to be a loner that other ravens seem to pick on.” The Anchorage newspaper headline read, “Off-Color Bird Faces Raven Racism.”

The rare off-color ones notwithstanding, ravens must normally distinguish one another by cues other than color. Movement might be one relevant cue. But that is a difficult cue to interpret, except that you know when it is absent.

Given the ravens’ predilection for poultry of all sizes, I provided my birds a recently killed raven that had been shot by a crow hunter. They reacted to this raven with loud, deep, rasping alarm calls. After some hours, they still ignored it. It was not eaten within minutes, unlike other birds I had given them that were pounced on in seconds. It was not eaten at all.

They would easily recognize a live crow. But a dead one? Would they eat that? My curiosity aroused, I had to observe their reaction to a dead crow. I presented a young frozen crow from my stock of roadkill in the freezer to Whitefeather and Goliath. Both birds erupted in
harsh, deep, rasping alarm calls, and just as with the dead raven, neither bird fed from the carcass. It eventually rotted in place. They did not even dig for the maggots.

Two months later, I presented another crow, a headless one, to the same two ravens plus Fuzz and Houdi. The reaction was the same. Two days later, on September 18, I again presented the headless frozen crow to observe their reactions more closely. That time, the reactions were weird, to put it mildly. As I entered the aviary with the crow in my hand, Fuzz erupted in the deep, long, rasping alarm calls normally given in response to ground predators. Within seconds, all four birds had joined in. At first, all made only the deep rasping caws. After a few minutes, they also made the rapid
rap-rap-rap
calls they usually give when a raven comes by. Fuzz then initiated several series of high-pitched, fluting
quork
s that I had never heard him give before. Whitefeather, the dominant female, suddenly went into an extreme crouching position (often referred to as a precopulatory display) in which she flared her wings widely and rapidly vibrated her tail. She crouched in place like that for minutes, as if glued to her perch. I had seen the same display used in entreaty, as when a subordinate bird was denied access to food or a bath. Then she erupted in knocking calls, the female power display. Houdi, the subordinate female, also did a mild version of the crouching display, but she didn’t knock. Fuzz did a lot of bill-wiping on the perch, a displacement activity common during times of conflicting emotions. I had never seen these behaviors toward other bird carcasses—those that they ate, and they usually ate at once.

After several minutes of intense interest, both Fuzz and Goliath went down to investigate the crow carcass. Only Fuzz, the most dominant male, touched it. He approached it in his macho, erect, male-dominance stance with smooth head feathers, gently touched the dead crow with his bill, and shouted directly at it. He stared at the carcass while doing several series of rapid
rap-rap-rap
calls normally given when a raven flies by in the distance, a call that I believe says, “Notice, I’m here.” He looked at the carcass for a time, then casually walked off. After that, none of the other birds paid the crow carcass any more
visible attention. I next gave them a dead cottontail rabbit, and they began feeding on it in seconds.

Seven days later, I presented the same frozen, headless crow still again. The response was similar to the previous experiment, except that Whitefeather knocked but did not crouch. I left the crow. Two days later, they still had not eaten it. After I skinned it and removed the wings and legs, Fuzz approached it in less than ten seconds and ate it.

Do ravens have inhibitions against cannibalism, and did they mistake the dead crow for a raven? Or are they upset by the black? I gave them a piece of black rubber they had never seen before. They made deep rasping alarm calls, but no
rap-rap-rap
calls. Then I tried red flagging tape. Same response. When I presented them with an almost pure white bird—a ring-billed gull—they again reacted with deep, rasping alarm calls. They did not eat it right then, either. But when I gave them a second ring-billed gull two months later, Fuzz approached it within several minutes, plucked it, and ate it. When I presented them with the weirdest bird facsimile I could think of, a plastic pink flamingo purchased specifically for them, they made no alarm calls. They ignored it. I then brought them a big, black, battery-operated raven fascimile that gave the speech, “The end is near, the end is near—ha, ha, ha, ha, ha,” when you touched a button. Long before I pushed this button, all four birds flew wildly about with their bills partially open in fright. Even though this fake raven was smaller than any of them, all acted afraid of it. None went near it or displayed to it. The “speech” it made later had little additional effect on them. Goliath, the big male, made deep rasping alarm calls. They apparently saw it as something strange and hence somewhat frightening. After I removed the toy raven from the aviary, both males went to their respective females and made throaty, hiccup-like calls with a downward inflection followed by a musical upward inflection. They showed their ears during these displays, which apparently were to reassure their mates of their strength and power. The ravens showed no alarm when I gave them the carcass of a black chicken. The black feathers didn’t fool them one minute; they went right to it to pluck and eat. I also gave them a dead adult opossum. They had never before seen one,
but in less than a minute, Fuzz approached it; then all came and fed. There is no easy explanation for these observations. That is why ravens are so interesting. Nevertheless, I think the experiments do show that body language is important to them for recognition, even to the extent of allowing them to distinguish between a raven and a crow, an otherwise easy task for them in live objects.

I am confident the birds do not identify each other by the markings I put on them, such as leg rings. No bird ever looked down to examine another’s legs before cozying up to it. Goliath never looked over Whitefeather’s shoulder when he approached on her left side, to check for the white wing feather on her right wing. When she molted and lost the white feather, he did not change his behavior towards her. Mutual preening (allopreening) is often accompanied by soft comfort sounds that may have individual characteristics that the birds recognize, but they did not “call” to identify themselves before beginning to allopreen.

Whitefeather’s white feather was mostly black
.

The relevant cues they use become more specific with age. Young birds in the first weeks or so of life are blind, and respond to any sudden vibration of the nest by stretching their necks up, begging loudly, and opening their mouths for food. The vibrations are normally caused by the adults’ landing on the nest edge. The young nestlings do not yet identify the parent as such, because their necks are directed straight up, regardless of the parent’s direction. After the youngs’ eyes open, they gape toward almost any moving object. With time, they learn increasingly specific details of their parents. By the time they leave the nest, they have learned to respond to numerous cues and to reliably identify whoever has been feeding them, be it raven parents or human foster-parents. Soon, they follow specific
individuals
, flying away in fright from strangers, both human and raven.

Vision is important in recognition, but I have no clue what they look for or see in another raven. They recognize me—I am the only individual who can regularly walk up to them to within one yard while they are feeding. If any other person comes within fifteen yards, they fly up in fright. I have experimented with them by giving or withholding clues about my identity, to see what cues were important to them. When my young ravens were less than a year old, they showed fright if I wore different clothes. They were startled and flew away from me when I wore a hideous Halloween face mask. Perhaps they used clothes and faces to identify different humans.

Tests with my four tame birds after they were two years old showed that more was by then involved. In one experiment, I came into the cage after having been absent for a week, wearing my blue jacket, snow pants, and snow boots, but I had pulled a knitted green stocking cap they knew well completely over my head, with tiny peepholes for my eyes. As I entered the aviary “faceless” on this and other occasions of the test, I was careful not to say a word to them, because I didn’t want acoustic cues to override all others. It was clear that my face was not the sole criterion they used to identify me; the birds were quite at ease, although they appeared to look me over more carefully than usual. In my next trial, I showed my face but wore new clothes that I had never worn near them before. The birds were still quite at ease. On the other hand, when I came dressed up in a bear suit they were quite alarmed, especially when I did the “bear walk” on all fours.

Ann, a neighbor, obliged me by taking part in the next experiment. As I expected, the same birds were wild with fright when she walked into the aviary. So far so good. We left, exchanged clothes, and came back. I wore Ann’s blue shirt, and she wore my boots, jacket, and snowsuit, and pulled the green stocking hat with the one peepholes in it over her head. Then she walked into the aviary again. She was masked and dressed exactly as I had been when the birds were quite nonchalant. The birds flew about in their cage in fright with open bills, although not quite as wildly as when she had come in dressed in her own clothes. Next, I walked in wearing Ann’s blue shirt and the ski mask. The birds were not fully at ease, as they had been
when I wore my own clothes and a mask, but neither were they wildly afraid. They were just moderately uneasy. When I pulled off my mask, they became totally at ease.

I next tested the responses of another group of birds that were wild-caught but had become tame after a year. I had on four previous occasions chased and caught these birds using a long-handled smelt net. I had tried to conceal my identity by wearing a black mask and wig during the chases so that they would later allow me to come close to them for my behavioral observations. When I came near the birds at other times, I had worn my “good” hat, the orange one that left my face bare. They always flew away from afar when they saw me coming either with the smelt net or wearing the black mask with wig. Did they know just the smelt net, or me, or my mask? Wearing my “good” orange wool hat, I entered the aviary and threw down a handful of oatmeal. They gathered around me like chickens. Okay, they were not afraid of me and the orange hat. As soon as I pulled the black mask out of my pocket, they all flew off. So they feared the
mask
. I asked Chelsea, one of my Winter Ecology students, to enter the aviary while wearing my orange hat. Results were clear: As soon as she entered the aviary, the birds left the main aviary, flying off into the side aviaries. She spread the oatmeal, and they all stayed away. When she came out of the aviary, the birds streamed back in to eat the oatmeal. I reentered and they stayed fully relaxed, feeding all around me. It was clear that the birds identified individual humans, regardless of what they wore or carried. However, one’s trappings can themselves be frightening to them, especially if they were associated with fearful situations.

The hiding of my face had not frightened one group of my tame birds, but I wondered if perhaps they had identifed me by my clothes. What about a
strange
face? I put on a grotesque face by crossing my eyes and rolling them up. It made no difference. I could still walk to within a yard of the feeding crowd (a later group). With dark sunglasses, I got to three yards. Apparently, my eyes didn’t contain the important clue of my identity of them. I tried limping in to them. That also got me almost equally close, but when I hopped on one leg they flew up at seven yards already. So they at least noticed my gait,
but my walk was either not the one deciding characteristic that held my “signature” for them, or else they knew very well it was me, and they were uneasy merely because of my weird behavior.