Mind of the Raven: Investigations and Adventures With Wolf-Birds

by Bernd Heinrich

  Years later, when I finally had tenure and ventured to try to solve a small question of behavior in ravens, I had occasion to hear reports of ravens behaving in ways that seemed both intelligent and strange, and although much of that could be dismissed as hearsay, there was nevertheless a sampling of the observations published in the scientific literature by respected and disciplined observers that hinted otherwise. The reports included ravens hanging by their feet (Elliot, 1977), sliding in snow (Moffett, 1984), snow-bathing (Hooper, 1986; Hopkins, 1987; Bailey, 1993), aerial bathing (Jaeger, 1963), flying upside down (Evershed, 1930, Täning, 1931), doing barrel-rolls (Connor et al., 1973; Van Vuren, 1984), social flying (Henson, 1957), using objects to displace gulls from nests (Montevecchi, 1978), using rocks in nest defense (Janes, 1976). Manual flexibility included carrying food in the foot rather than the bill (Owen, 1950), foot-paddling (Ewins, 1989), and rolling on the ground to avoid a peregrine (Barnes, 1986). Other strangely flexible behavior involved covering their eggs (Davis, 1975), poking holes in the bottom of their nest on a hot day (Gwinner, 1965), carrying their nestlings (Stoj, 1989), bonding to a crow (Jefferson, 1991), catching doves in midair (Elkins, 1964), and attacking reindeer (Ostbye, 1969). The reports in aggregate hinted that studying ravens would be not only interesting but also challenging.

  Having now lived on intimate terms with ravens for many years, I have also seen amazing behavior that I had not read about in the more than 1,400 research reports and articles on ravens in the scientific literature, and that I never could have dreamed were possible. I have become skeptical that the interpretations of all ravens’ behavior can be shoehorned into the same programmed and learned responses-categories as those of bees. Something else is involved, and I wanted to make some sense of it. My concern with imponderables, however, has usually been secondary to the quest to find out what they do, which to me is more important than deciding how to label it. Ultimately, knowing all that goes on in their brains is, like infinity, an unreachable destination. The interesting part is the journey.

  My goal here is not to be authoritative. Instead, I sketch the world of a magnificent bird that, as we shall see, has been associated with humankind from prehistoric times when we became hunters. I focus largely on unpublished observations, experiments, and experiences that I hope will engage you to participate in the quest of exploring another mind.

  Houdi at ease and confident, showing small hint of ear feathers.

  ONE

  Becoming a Raven Father

  THE FIRST PREREQUISITE TO STUDYING any animal is to get and to stay close. You must be able to observe the fine details of its behavior for long periods of time without the animal seeing or feeling your presence. That’s a tall order with wild ravens in northeastern America. In my part of the country, where food is sparsely distributed, ravens may range over a hundred square miles a day, and they fly away at the mere sight of a human. Ravens are shyer and more alert, and have keener vision than any other wild animal I know, making it even more difficult to watch their natural undisturbed behavior.

  Given these difficulties, I felt I needed to try to obtain young and to be a surrogate parent to them. It was perhaps the only way to learn about many aspects of their intimate social behavior. Obtaining and living with young ravens has its inconveniences, not the least of which is making the hazardous ascents to get them from the nest. The trees that ravens like to nest in are not the ones I like to climb.

  The last few patches of winter snow were left in the shady places under fir trees. The ice had just melted off Hills Pond, and the first warblers were back. But in Maine at the end of April 1993, still a month before the maples would leaf out, that year’s baby ravens would already have a coat of black feathers. I was on my way to two different nests. I would take two young of the clutch of four to six I expected to find in each nest. I would then have to attend to every need of the young birds.

  It was snowing, and the great pine tree with the first ravens’ nest was swaying in the north wind coming across the lake. I wanted to run, but I held myself to a walk, trying to conserve as much energy as possible for the climb ahead. More than once before, I had been frightened when I found myself hanging on to a thick limbless pine trunk as strength ebbed from my arms. The void above the tops of the fir trees seemed to expand as my grip grew less secure.

  White feces were spattered on the ground below the nest, a sign that the young were already beyond the pinfeather stage. At this nest, which I had visited often in previous years, only the adult male scolded me; the female always left when I came near. At other nests, both members of the pair may scold, both leave, or one or both remain at some distance.

  After carefully putting on climbing spurs and adjusting my backpack, I put my arms around the tree and started. Go slowly, I kept telling myself, one step at a time. I tried to keep looking up, not down. I got very tired just as the solid limbs were getting closer. Fortunately, having trained over the winter to do chin-ups, I was able to sustain the effort. As I hauled myself up onto the first solid limbs, I felt elated. I had once again escaped the fate of some other ornithologists in similar situations. George Miksch Sutton fell from a cliff while climbing up to a raven nest, but was saved by falling on a ledge before hitting the bottom of the cliff. Fellow raven researcher Thomas Grünkorn once fell eighty feet out of the top of a beech, breaking his back in two places. Miraculously, he lived and did climb again (see Chapter 7). Gustav Kramer, an ornithologist studying wild pigeons, died when rocks came loose as he was climbing up to a cliff nest. I am quite frightened of cliffs, by comparison feeling almost safe with tree limbs to hang onto.

  The tree was swaying mightily in the gusts, but it had not been blown over in worse gales, and it would not fall or break now. Besides, there was nothing I could do about it. So no worries.

  Four fully feathered young hunkered down in a very soggy nest. It had rained steadily for the last two days, and the heavy, waterlogged nest was badly tilting because one of the supporting branches was too thin. The four young were very chunky, clumsy, and cute. When I lifted two out to put them into my knapsack, I noticed their huge bare bulging bellies. They didn’t struggle or complain, and the climb back down was easy.

  With four young finally resting in the bottom of the knapsack, I hiked home to put my new charges into their new nest—a basket packed with dead grass and leaves almost all the way to the top, so that they could defecate out over the edge. I talked to them in low soft tones, and they immediately broke their silence and answered in raspy raven baby talk. They were almost feathered out, and looked at me with bright blue eyes (which would turn gray near fledging and brown by winter). They raised pinfeathery heads and opened their big pink mouths (mouth linings and tongue turn black only after one to three or more years, depending on the birds’ social status). They were begging to be fed! Such trust, especially after just being taken from their nest, is unique for a bird already at least a month old. It is especially surprising given that ravens are innately shy of anything new. As adults, ravens in Maine are among the most shy of all birds. These young had long been exposed only to their parents and siblings, yet they responded to me unabashed. Did they somehow hear something in my voice that put them at ease?

  Their sounds tugged at my heart, and I sprang to action. We quickly established a rapport and I chopped up whatever meat I could find, usually roadkills, and fed the ravens bite-sized chunks at about hourly intervals, just as raven parents do in the wild. Baby ravens and crows need a pharmacopeia of proteins, minerals, and vitamins. I fed mine minced mice, grubs, eggs, fish, and chopped frogs. I’ve seen people try to raise baby crows as they would raise their own babies, on milk and bread. If the young birds didn’t die, they suffered from rickets or some other nutritional debilitation that left them crippled.

  Parenting in animals has been honed by natural selection over millions of generations, and greatly diverse parenting skills have evolved. Details are critical, and anything different from the species’ norm
is likely to be harmful. Young passerine birds need a high-protein diet that contains all the vital nutrients in proper proportions. During their critical growth period, muscle, nerve, and bone are built up so fast that body weight may increase 50 percent or more per day. Feedings therefore must be frequent.

  On the first day, I fed the four birds six mice, four hen’s eggs, two six-ounce cans of cat food, ten ounces of puppy chow, and a couple of mouthfuls of beans I had prechewed for them. They had each gained 600 grams of body weight after they had eaten 8,100 grams of food.

  To give you some idea of the food a pair of ravens must provide for their family, I offer here a list of what I fed to a group I parented some years later, six nestlings at about five weeks of age.

  Day One: One woodchuck and one snowshoe hare (roadkills that I froze and then chopped up—skin, bones, guts, and all—into bite-sized chunks and thawed before feeding).

  Day Two: Three red squirrels, one chipmunk, six frogs, eight chicken eggs (crunched up shells and all).

  Day Three: Two gray squirrels, five frogs, six eggs, six mice.

  Day Four: One hindquarter of a Holstein calf.

  In a few more days, as their appetites picked up, each could swallow six woodfrogs, two mice, one after another in just one meal, and each young was ready for a repeat performance of the same in just one or two hours.

  Raising baby ravens has always been a joy to me, but I must explain the difficulties entailed in raven parenthood. Never mind stopping for and chopping up roadkills. Or the fact that a raven will never be housebroken. As for going away for a Saturday afternoon—forget it! Remember, a young raven needs to be fed at least every few hours, and it will require your devoted attention every day. Without that attention, the bird will not bond with you and will become wild and “unpersonable”; it won’t give anything back. Basically, you will be stuck with the world’s worst roommate. To some, that may be a small price to pay. I just wanted to be sure my readers know what the price is.

  There is also the bird’s side to consider. If integrated into a human family, it will be where it wants to be and it will likely be happy. If it is not bonded to a family member, to which it needs constant access, it will feel imprisoned. Finally, there is also the official point of view to consider. There is no legal qualification for having a human baby, whether or not one is capable of parenthood. But it’s not so easy to “have” a raven baby. For that you need both state and federal permits, which require providing a thoughtful rationale.

  If you seek contact with a wild bird that will bond, that will “talk” (and even learn to sing tunes), and that will be practical to keep, I recommend adopting a starling. Mozart had one, and evidently he was extremely fond of it. Starlings are black, and when in breeding plumage they glisten even more than a raven does. They are far better voice mimics, and they are easier to keep. Best of all, they require no permit, because they are an exotic “pest” species that competes with our natives. The main annoying thing about them, at least the young ones, is that they will unceasingly yell in your ear and open their bill in it, as if prying under leaves to check for worms. A wild goose won’t do that, but it will fly behind you if you leave in a car, as if believing you’ve joined a flock, so you can’t drive in heavy traffic. Each species has its own particular innate responses that have been fine-tuned through millions of years of selection in the natural environment.

  Trying to parent wild animals is discouraged these days, perhaps in large part because it is difficult to do and often goes awry in unanticipated ways. When I was a boy, my friends and I raised young crows, jays, robins, sparrows, skunks, raccoons, hawks, owls, geese, and a starling. What we learned not only applied to our pets, but perhaps was also a lesson in diversity, in patience, and in tolerance.

  The food that you give baby birds creates even further chores and responsibilities for you. The meat ingested by the young is thoroughly processed into a near-equal volume of liquid waste called “mutes.” Raven parents scoop up the mutes in their mouths as they are being ejected, so as not to soil the nest. After the nestlings are a week or two old and the volume of mutes picks up, the parents no longer eat them but carry them off to discard away from the nest.

  I lucked out. My four young ravens were already old enough to back up to the edge of their nest. They stuck their rears out over the edge and vigorously wiggled their tails from side to side like a reversible rotor. Only then did they finally let go in a stream that shot out two to three feet.

  Despite the young’s early bowel control, all that changes as they get older. Eventually, near fledging, they lose it. They go at will, with emphasis on achieving maximum distance. Once they have left the nest, the young become ever more nonchalant about waste elimination. That’s why they can’t be housebroken.

  How can the raven parents swallow mutes, the wastes of not only the digestive but also the urinary system? First, raven mutes normally aren’t malodorous, unless the baby bird is sick or overfed and the food is not thoroughly digested. Raven mutes are mostly a white secretion of uric acid crystals from the urinary tract. They aren’t at all like chicken manure, which, though it smells horrible, is mixed with sawdust and fed to cattle, so that we eventually eat it indirectly.

  All protein metabolism results in toxic, often smelly nitrogen waste products that the body must get rid of by flushing with water. That is why the more proteins we eat, the more water we must drink. Paridoxically ravens live on meat, yet they can get by without drinking, except at high air temperatures when they need water for cooling themselves evaporatively from the mouth and respiratory surfaces. That’s where their nonsmelly mutes come in. The white uric acid they contain is nontoxic and relatively nonsoluble in water, unlike the raw sewage, urea, the primary mammalian waste product. Thus, large amounts can be excreted with very little water. It is voided as a white odorless paste rather than a yellow liquid. As a consequence, a raven is preadapted to get by on little water, and the parents’ nest-hygiene chores are easier.

  Raven parents shove food deep down baby’s open gullet.

  Aside from the mutes that can be bothersome, young ravens are vociferous, and not very melodious for a so-called songbird. Ravens are unjustly accused of being poor or uncaring parents because their young beg for food so noisily. Although hunger increases the volume of their begging yells, that volume is itself a product of natural selection. The young may outshout each other in competition to gain parents’ attention, but the shouting also attracts predators. Ultimately, the upper volume of noise that evolution allows is capped by predation. If the nest is secure, the cap is high.

  In ravens and other birds, there has been tremendous selective pressure to grow fast and develop flying ability soon after birth. A sparrow can grow to full weight in a mere ten days, but in a raven, growth to maximum weight takes about forty days. Young ravens about a week old spend most of their time sleeping while being brooded by the female. They are still naked and unable to regulate their body temperature. They pop up their heads and beg whenever one of their parents gets up and makes short little nasal “gro” calls. Later, after the female no longer incubates them, they sleep, waking and begging whenever a parent flies toward the nest.

  LEFT: Recently hatched chick. RIGHT: About a week later, eyes still closed, pinfeathered.

  At about three weeks of age, when they feather out, there is constant stirring and nonstop activity. At any given moment, one young raven may be lying down and sleeping with its bill tucked into the feathers on its back, while another stands, stretching its legs and one wing at the same time, then perhaps reaching with one foot over its back to scratch the back of its head with a toenail. Another may stand on the rim of the nest, vigorously flapping its wings; a fourth may pick and yank at a loose stick, while a fifth is singing. The singer will have a dreamy vacant look about him, frequently fluffing out his head feather and erect “ear” and throat feathers. He’ll be acting like an adult male experiencing confidence and/or dominance. He’ll cock his head, h
alf close his eyes, and utter queer gurgling, warbling calls that vary crazily in pitch and volume with no detectable rhythm. When a fly buzzes by, all are distracted. Heads shoot up and all watch the insect intently. Seconds later, activities resume. From a few seconds to a minute or so, each individual switches from stretching, preening, wing-flapping, sleeping, playing with sticks, and shaking. There is little indication that the activity of one bird has any influence on the activities of another.

  A human baby of the same age of six weeks cannot yet turn himself over, but he can almost hold his head up. If a human baby can’t reach the nipple, he gets lots of assistance. The baby ravens must hold their heads up high to beg for food from the day they hatch out of the egg. Those who don’t, won’t get fed. Baby ravens snatch mosquitos and black flies out of the air in a superb display of eye-bill coordination at only three weeks of age. Even before leaving the nest, they can pick up food and feed themselves, but they won’t do it if begging is an option. They can scratch the back of their head with one foot, sleep standing up, and groom themselves extensively.