Mind of the Raven: Investigations and Adventures With Wolf-Birds (37 page)

As always with ravens, the story is in the fine details. First, I had given the birds their last fresh pan of water for bathing seven days earlier. For a young raven, seven days without a bath is a very long time. The birds prefer to bathe every two to three days, and one of the most consistent variables that determine whether or not and how much they bathe is the number of days since the previous bathing session. The exception being, as previously mentioned, that when Houdi was incubating eggs and brooding young, she didn’t bathe for two months.

With humans, temperature is such an important bathing variable that we could predict the number of people at a beach and call it the bathing law. To my ravens, temperature (except at 32 degrees Fahrenheit and below) seemed unimportant. With the total sample of 582 baths taken at temperatures from 33 degrees to 90 degrees Fahrenheit, temperature just wasn’t an important variable. I finally did get my zero point on the graph of bathing frequency versus temperature at an air temperature of 15 degrees Fahrenheit below freezing. But in that instance, maybe the water wasn’t available long enough before it froze. So they snow-bathed instead.

Perhaps the most important factors determining whether a raven will take a bath is whether it sees another bathing. As soon as one of my six started to take a bath, all of the others rushed to the water dish and tried to bathe as well. Of course, a contest ensued, with the most dominant birds being first. If a subordinate bird hopped into the bath, a dominant bird simply shoved it aside. Sometimes a subordinate then prostrated itself in extreme submissive displays, as if pleading, but that never helped. Each bird took multiple baths, whether it really wanted to or not. It went like this: When a dominant finished its bath and hopped out to preen itself, the next would hop in and start to splash. The dominant, who had just done all the bathing it wanted,
then almost always stopped its preening and hopped in again, in order to displace the bather. Having splashed some more, he would hop out to preen again, and so on. After a half-dozen to a dozen such exchanges, the dominant male would finally allow himself to preen in peace, and the second in line would bathe, behaving in the same way to the next in line below. So it went on down the line to the most subordinate bird, who could bathe in peace.

Given the above, bathing in the mud puddle suddenly seemed rational. With all the birds competing at the water pan to bathe, one of the frustrated subordinates suddenly got the bright idea to use the other water, the mud puddle. The more dominant bird, at that very moment bathing in the clean, roomy water pan, immediately jumped out to chase the subordinate bird out of the mud puddle. He jumped into it himself and churned the puddle into a muddy broth. The vacated water pan with nice clean water was, of course, instantly used by another bird. The mud bather’s frolic was therefore brief as, hopping rapidly, he returned to evict the opportunist from the water pan. Mix six birds into the fray, each trying to bathe and at the same time keep the others from bathing in a game of king-of-the-bathtub, and you end up with a frenzy. That’s the reason there was a record of forty-nine baths in thirteen minutes. It was fun to watch, but it sure threw a curveball at my efforts to graph bathing frequency on any and all of the different variables that I had anticipated might be relevant. Even after taking notes on the context of 582 baths, I still had no idea why they bathed when they did. So I had to let it drop, as just another one of those interesting but unpublishable idiosyncratic results that might, like many others, only confuse some current academic thought.

A half year later, the results were different: The older ravens had become less enthusiastic bathers and were less influenced by the activity of their peers. But on November 15, at 48 degrees Fahrenheit, after they had not bathed for a month, the six took fifty-seven baths in seventy-eight minutes.

The most commonly seen raven play occurs high in the air. The following examples show some of their games.

Hanging games
.

In the autumn of 1983, Johanna Vienneau of New Hampshire was hiking above the tree line on Baldface Mountain with her dog, who was about twenty-five feet ahead of her. A raven came flying over and dropped a rock about an inch in diameter a foot away from the dog, a near-hit.


Cedric Alexander, a wildlife biologist from the Vermont Department of Fish and Wildlife, told me that on December 5, 1993, an employee of his came into the office reporting that a raven had dropped a four-inch sprig of spruce while flying over him at about three hundred feet.


Rod and Amy Adams and Eliott Swarthout, who were employed in September and October watching hawk migrations at Lipan Point on the South Rim of the Grand Canyon, wrote me: “Once we have seen a raven drop a rock in flight and successfully catch it. Once we also saw a raven drop a red object and catch it. Also dropped and caught were a coyote tail, and a vulture feather—the latter was missed by six ravens!” (Could they really catch rocks but
miss
a feather?)

Locking talons in flight
.

I’ve seen ravens loitering for hours in the updrafts of the hills and mountains of western Maine. Again and again, they ride the air elevators and dive down in pairs or small groups. Once, on November 19, 1992, I was in a spruce tree watching groups of five to twenty birds return to a roost. Most were flying methodically. Suddenly one, who was coming back alone at high altitude, closed both wings to its sides and bolted straight down. In rapid succession, it made three 360-degree spins around its axis. Then it extended its wings, banked slowly, and descended in a graceful arc to land in the top of a pine near the roost where others were already settling for the night. Why the extra flourishes? Do the birds act out something they visualize in the brain, which other birds don’t? Or do their odd behaviors just “happen” without their conscious knowledge? Could we suddenly do a back-flip without thinking about it first? If so, why should a raven be capable of it, if, as is generally presumed, they are unconscious?

At Grandfather Mountain (5,965 feet) in North Carolina, a plaque is given to anyone who can maintain an hour or more sustained flight with a hang glider. Those who earn the honor are said to belong to the Order of the Raven. “They [ravens] fly with the gliders, usually staying five to twenty-five meters off the gliders’ wing-tips. Sometimes they get playful and dive past the glider, coming within a few feet. Other times they stay directly above or below, often getting pretty close,” Michael E. Miller told me. What fun it must be to glide with ravens!

Tim Hall, also a former hang glider and paraglider pilot, wrote me: “I have had the pleasure of sharing the air with ravens on many occasions. I was paragliding in the mountains about eight miles east of El Cajon, California, traveling above a 3,000-foot cliff, when I came upon a group of about ten ravens. They were swooping and doing barrel rolls. After a few minutes, another raven joined the others. This raven was carrying what appeared to be a twenty foot long about two inches wide white plastic streamer, similar to surveyor’s tape, in its beak. It started swooping down through the others, folding its wings and swooping back again. After doing this several times, it started handing the streamer to other ravens. Several ravens took turns catching the streamer, swooping with it, then releasing it, and the next raven took its turn. None played ‘tug-of-war’ with it. This activity continued for about twenty minutes. Those ravens that did not participate landed on a bare tree at the top of the cliff and appeared to watch the flying antics of the others.” Miller’s and Hall’s information is valuable and hard to get. Not many biologists do field observations from hang gliders, although researchers watching dolphins from boats observe very similar antics, including bow riding, chasing, and object play.

Not all the raven’s playthings are inanimate. Wildlife biologist George B. Schaller reported African white-necked ravens’ (
Corvus albicollis
) play with gorillas at Kabara, in East Central Africa, in his book
The Year of the Gorilla:

“The Virunga range spread glistened in the heat. I sat on a grassy knoll with my back against a bluff, my feet dangling over the depth of a dusky canyon. Ahead of me were the gorillas, and beyond them the slope swept upward, the breeze moving the green and silver leaves of the senecias until I was dizzy with the light. While eating my lunch, I spotted the ravens high above me, small black spots against the white of a cloud. When I whistled, which to the birds signified food, they descended in leisurely arcs. [The African ravens are not nearly as skittish as the northern raven, and the Schallers had tamed this wild pair.] The gorillas ducked when the gliding shadows of the birds passed over them, and the male jumped up and roared; females screamed, some looking at me, others at the ravens. Then, as if in play, the ravens
swooped at the gorillas, diving low over them again and again. The male grew angrier than I had ever seen him, and the females milled about in utter confusion. The apes obviously failed to find this a game, and the ravens, well satisfied with their mischief, landed in a heather tree near me to consume the rest of my lunch. Then they headed into the valley, but an hour later they returned and again flew in unison at the gorillas.”

I will not indulge in endless speculation on the ultimate benefit that these many kinds of play could have to ravens. Your guess is as good as mine. There are few data to prove or disprove almost any hypothesis we might come up with. Nevertheless, some types of play that are common in ravens do have demonstrable effects on their breadth of diet and their interactions with carnivores.

Ravens are omnivores who, with a combination of following others, curiosity, and learning, are able to find and utilize appropriate insects and fruit as these foods come into season in any one environment. This behavior of ravens differs from the more stereotyped innate responses of say, a red-eyed vireo that looks for caterpillars under the leaves of deciduous trees, or a flycatcher that hunts flying insects by sallying from a perch, or a kingfisher that dives for fish. These birds undoubtedly learn, but they are programmed to be exposed to a very narrow niche. Ravens seek wide exposure and experience, and profit from it. For that they have evolved curiosity (Chapter 5).

Ravens get significant amounts of prey by hunting, scavenging, and by association with predators. All of these potential food sources are also opened up to them by learning under the broad rubric of
getting to know
potential prey and predators. The exposure to these indirect food sources is achieved with play and curiosity, followed by learning. Object manipulation is a kind of play that results in identification of what berries, insects, and other objects might be appropriate to eat. Similarly, getting to know prey and predators is also proximally play, in that the behavior is not done initially out of motivation for immediate food reward. Even after being fully satiated, Jack, my pet raven free in the Maine woods, did not hesitate to fly in pursuit of birds or butter
flies; and I once even saw him take off after a snowshoe hare, annoy a languid old dog, and taunt an aggressive big cat. He quickly learned what he could and could not get away with.

In the wild, ravens are well known to take the measure of wolves, coyotes, and eagles. Some miscalculate. For example, Jim Brandenburg once filmed “an aggressive, dominant, nearly black wolf as it grabbed and shook a raven.” In that particular case, the raven got loose and escaped, but not all who miscalculate so badly are likely to live. Practice at the dangerous game of testing the limits of the predators could pay huge dividends. This strong tendency, seemingly to court danger, is another record that is engraved in their behavior, of an ancient evolutionary history with carnivores. As with human young, these natural tendencies for specific play are most obvious early, to be later blurred by learning and cultural influences.