As I muscled my way up the tree and finally maneuvered round one side of the thinning trunk in the top branches to look into the nest, I saw five healthy young. They were just beginning to feather out, and were above half adult weight already. At that age, the young had no fear of anything near the nest. With blue eyes wide open, they raised their long scrawny necks to me, begging for food. I, in turn, loosely twisted a soft pipe cleaner around the neck of each one. None of the birds showed the slightest sign of having noticed, and each one either continued begging exactly as before or settled deep down into the nest to sleep. Three hours later, after I presumed the adults had made three to four foraging trips to the nest (and after I had adequately recovered from my arduous climb), I returned and climbed the tree again.
As before, the young were calm, and they begged. I noted not one lump in their throats. All the pipe cleaners still were attached. What was happening? Then I saw three loads of meat on the edge of the nest. Each load, which apparently had been regurgitated when it couldn’t be swallowed, was a solidly compacted mass, the size of a 35 mm film roll. It was red muscle meat, now almost black from partial drying, and it was leathery, like moistened beef jerky. It was definitely not frog meat, insect meat, snake meat, freshwater mussels, or fish meat. I took it all, and temporarily removed the pipe cleaners long enough to distribute the paper cup full of road-killed ruffed grouse meat I had brought up with me. It seemed more than a fair exchange for this leathery, semidried stuff.
The three regurgitated masses of meat each consisted of numerous pieces of partially dried, dark red meat that had been compacted together. It was not fresh by the smell of it, but neither was it rotten. It was coated with a film of slimy saliva. Most important, there were many compacted deer hairs worked into the crevices of the numerous pieces of meat, indicating the deer hair could not have come from the nest itself.
The meat had more clues. It contained a sprig of a green moss that grows in shady moist places on the ground. It also contained partially dried but green fir needles. Fir needles of that color do not just drop from live twigs. I’ve never seen fir twigs, branches, or needles in a raven nest. Fir trees hardly ever lose live limbs that would then shed green needles, and needles turn color before being shed by live trees. So the partially dried green fir needles probably came from fallen live fir trees, whose needles dry quickly and detach without first turning color. I suspected the deer meat had come from a cache on the ground among moss under dead fir branches near a lumbering operation. Skidder operators regularly carry rifles in their cabs. Deer in the winter have no fear of skidders, and they aggregate where loggers provide easy paths through the deep snow to felled trees with lots of buds to browse from.
My suspicion that the three feedings were from cached meat was strengthened the next day when I repeated the neck ringing. That time, in four hours the parents again delivered at least three wads of deer meat that sat neatly in place in the birds’ gullets. This was fully moist pink meat, not partially dried like yesterday’s. No moss and no fir needles were attached, only more deer hair. These meat portions likely came directly from a deer carcass. I was satisfied that regardless of what else the local Maine ravens may feed their young, at least at this nest they fed their young venison.
It might be supposed that the steady stream of calf carcasses I had provided during the preceeding ten winters in Maine might have been beneficial to the local ravens, helping them rear many successful broods. The fact that only four of eighteen potential nests were successful in the previous two years argued against this. I knew of no data from anywhere for such low nesting success by ravens (although I would later learn of very telling exceptions; Chapter 23). My sustained supplemental feeding had probably not helped the breeding pairs. The calves I’d brought attracted crowds of vagrant juveniles. Since no carcass had gone unused by these crowds, none would have been a reliable long-term food source for a breeding raven pair. Given the vagrant crowd, most of the deer carcasses in the woods I didn’t know about were probably equally transient. In contrast, in Vermont, where the breeding density of ravens is similar to that in Maine, I had provided only one large animal carcass at a time, and then not as regularly. These carcasses were almost never eaten by crowds, and they lasted months. Nest failures in Vermont still occurred (14 percent out of my total of thirty-five nestings), but not nearly as frequently as at my study site in Maine with regular supplemental feeding, where 48 percent of sixty-eight nests failed. If my food supplementation in Maine had an overall effect of increasing nesting success, then it was for ravens hundreds of miles distant from the site, not on the site itself. Given these thoughts, I wanted to get even more food samples from the young, and decided to repeat the observations for one more day.
It was spitting snow on the morning of May 8 as I went back to the cemetery nest. As usual, one member of the raven pair was at the nest. This bird was relatively tame. As she scolded me from the top of a neighboring pine, I noticed that she wore one of my rings on her left leg. The young were stuffed and sleepy. None begged. Immediately after I ringed their necks, two closed their eyes and resumed sleeping.
When I came back to the cabin, the snow had stopped and the sky was clearing. My company, Kim Most and Lori Friedman and their friend Kerry, University of Vermont students and raven helpers all, were baking fresh bread. I drank a cup of coffee and sat on the front step, listening to the energetic song of a winter wren. A solitary vireo called languidly from the mixed hardwood-conifer woods in the back. Then I heard the yells of a raven down toward Alder Stream, in the direction of the clearing a half mile from where I had dropped off six dead cut-open calves two days earlier, and I expected it would be many days before a raven would find them, and many more before they would dare to go to it and start feeding. Looking up into the sky beyond Alder Stream, I saw several ravens dancing high in the sky, then diving straight down and shooting back up. Such an aerial display, and the yelling, never fail to attract me, or other ravens. We took off as a pack of four, to see the ravens and be educated, and be reminded of Aldo Leopold. In A Sand County Almanac (1949) he had so aptly written a half century ago: “I once knew an educated lady, banded by Phi Beta Kappa, who told me that she had never heard or seen the geese that twice a year proclaim the revolving seasons to her well-insulated roof. Is education possibly a process of trading awareness for things of less worth?”
The southeast-facing hillside down to the brook had recently been logged. Poplar sprouts some five to six feet tall had grown in the previous year, and deer and moose had come to browse them. Curled fuzzy and brown fern fronds emerging from the ground showed pale green hairy stems below. Down by the brook, the alders were unfurling their catkins, but no green shoots were yet showing through the dry, curled, yellow swale grass that rustled as we walked through it in single file. As John Fowles points out in The Tree (1979), nature is, unlike art, created as “an external object with a history…but also creating in the present, as we experience it. As we watch, it is so to speak rewriting, reformulating, repainting, rephotographing itself.”
We jumped over the eroded beaver paths that had become canals leading into the brook. Along the water where the grass had been matted down, we saw brilliant green sharp tufts of grass rising straight up like phalanxes of short, erect spears. The burgundy stems of the red osier dogwood along the stream lent a striking contrast. The various colors blended pleasingly, because all the colors as they are arranged in nature are “complementary.” Nature is the standard for truth and beauty.
We stopped on a cleared slope next to the stream where a large pool reflected bright light like a mirror, making it impossible to see down through the brown water to the black bottom of mud and rocks. Fluffy white clouds drifted from north to south far above the black silhouettes of the pointy firs and spruces ahead of us, beyond which lay the clearing with the calves, where we could hear the ravens. I was feeling the pulse, but I was only beginning to have a sense of what was going on by getting to know their world. I hoped the unfolding
of that world would someday create a story where all facts would be meaningful. All data and all observations would be like flecks of paint that would, when seen in total, reveal a masterpiece of evolution.
Ahead of us, just over the spruces, I watched a plume of ravens rising high into the sky, up into the white clouds. The sky seemed black with ravens. I estimated there were about seventy to ninety birds. A brown eagle, possibly an immature bald eagle or a golden eagle, was circling among them. The large raven group split into two major regiments, then smaller squads of a dozen or fewer peeled off. Repeatedly they dived, tumbled, and spun, and rose again on outstretched wings.
We crossed the brook. When we reached the clearing, about a dozen more ravens flew up from the pile of carcasses. Most of the meat from these calves had already been stripped. We quickly built a blind of spruce branches nearby, so we could watch the action from up close later on. Then we returned to the grassy slope of the brook to bask in the sunshine and to float on a log raft in the pool in the middle of the icy stream. A winter wren sang, and a golden-crowned kinglet made its high-pitched contact calls in the fir thicket near the water. The time passed quickly. Time came to leave the raven show and to climb the pine again to retrieve the food from the ringed young and to feed them.
The previous pattern of behavior and feeding at the raven nest held up. As before, one parent was always at the nest. The parents or parent had this time brought six packets of dried meat in five hours with telltale deer hair folded into them, and one packet of fresh deer meat. This pair clearly relied on a deer carcass. Four of the feedings still in the youngs’ throats weighed a total of 75 grams and were composed of twenty separate little pieces of meat. Additionally, the parents had fed one of the young some very recently cached food—a piece of sausage along with well-chewed whole grain homemade bread. I knew, because I had left these items on the nest edge after retrieving the birds’ food the day before. Just as I was leaving, one bird returned carrying food in its bill. Its voice was muffled, as if it was trying to talk with a full mouth.
That evening at the cabin, we enjoyed a meal of fresh bread and pasta. We built a fire in the pit and roasted marshmallows over the coals. A woodcock displayed on and over the clearing beside us. Before it left to go hunt earthworms for the night, we also heard a few agitated raven squabbles from the pines nearby. That meant there was a temporary roost there, probably of some of the ravens that had been recruited to the carcasses. I felt at peace and slept soundly.
I woke at about 4:30 A.M. as the eastern horizon was beginning to lighten up. Without bothering to make myself food or a cup of coffee, I stepped outside. It seemed warmer, and there was not a hint of cloud in the sky anywhere, nor was there a breath of wind. All the sounds were magnified, and a dawn bird chorus was starting—the fluting hermit thrush, the peripatetic winter wren, the dee-dahs of chickadees, the nasal twangs of the red-breasted nuthatches, and the long sad whistles of the white-throated sparrows. The woodcock must have had good foraging in the night, for he was strengthened enough to perform his athletic display, repeatedly rising hundreds of feet into the sky like a giant hummingbird and then whistling and diving again in the dim morning light, just as he had done earlier at dusk.
The ravens at the nearby roost were still silent, and I had time to get into my newly built spruce blind across the brook by the calves. By 4:50, I heard the first raven calls, and soon after that they started arriving by ones, twos, and threes. I expected this, as the birds had already fed well here, and indeed most of the meat had been taken in two days. Those that would come now did not need to follow crowds of others. They could come at their own discretion. As each raven or small group arrived, they settled into the bare branches of a nearby poplar tree, and I saw them as dark silhouettes against a gradually lightening sky. They preened, occasionally shook themselves, and sometimes made soft cooing sounds. There would be no yells today, unlike a day or two earlier, before they first began feeding here when they were still afraid.
By 5:25 A.M., more than twenty birds had gathered in the poplar, and ten were perched in another tree. A group of four or five swooped down to the calves near me. Within five seconds, all the others except two came down, and the pile of calves was then quickly enveloped by ravens. Even before the sun was over the horizon, light reflected off their backs, with the yellowing sky as a backdrop above the silhouettes of trees on a low distant ridge. Occasionally, still another bird came in over the trees, set its wings, and glided silently, low over the ground near the calves. Others left at intervals.
Except for occasional bickering, the ravens were quiet, as I’d expect this late in the feeding cycle. The most conspicuous sounds were the other birds of the forest—the peculiar cadence of the sapsucker’s drumming on a dry branch, a “song” where the beat changes but the tune stays the same, and the low thumping drumroll of a ruffed grouse starting strong and slow with hollow-sounding wing-beats ending in a blur of sound. Purple finches, and the first ovenbird so far this spring, called.
About thirty ravens eventually fed at the calves or loitered around them in the near-darkness. None of the new birds we had captured or marked this year were among them. Only one marked bird was in the crowd, a female with a yellow wing marker with the letter W on it. I had sighted her a number of times during the last several years.
Daylight arrived. Gently, ever so slowly, I moved a small spruce spriglet from my line of vision. All went smoothly until one bird noticed something amiss—perhaps my slowly moving hand through the curtain of fir twigs. As always happens when one of the group leaves alarmed, the whole group left the bait in a wild clatter that was so sudden, so violent, that their contagious fear was almost palpable. Not one bird uttered a sound. For many seconds, the birds flew wildly all around, not knowing what or where the threat was. They made several passes around the clearing, then left. I then also left to check again on what the youngsters were being fed.
I climbed up to the nest four more times, to monitor what the young ravens had been fed for an additional 15.5 hours. During that time, they were fed thirteen loads of food. On May 12, three loads were again semidried deer meat. The other load was a white chunk, possibly of suet (from someone’s bird feeder?), along with two crushed robin’s eggs. On the next day, I recovered six food loads. All were fresh deer meat.
May 14 would be the last day I could get data, because I had to leave for a week. The young were by then already feathered out and would soon be cantankerous and uncooperative. When I got to the nest, I pushed the lumps in their throats up with thumb and forefinger, as I had done before to deposit the regurgitate into a plastic bag. From two birds, I recovered chunky semidried deer meat, much as I had been collecting before. A third bird again held a chunk of what looked like white suet. Again, the suet had something blue with it—the sky blue color of robin’s egg shells. Only this time, something was different. A fully intact robin’s egg emerged from the young raven’s red mouth.
It was amazing that the delicate egg had not been crushed in the young bird’s mouth and throat. Even more miraculous, the egg had survived being taken out of the robin’s nest by the adult raven. As I delicately cradled the fragile egg, trying hard not to break it, I realized that the raven must have done the same. Whenever I’ve given a mouse to any raven, I’ve heard the crunch of breaking skull or vertebrae as the bird took it in its thick bill. There is also an audible crunch when ravens take an insect. They also squeeze down hard on a piece of meat. Most objects are also pecked. The bird that raided the robin’s nest had to reach down into the deep nest cup and grasp the egg in its thick, hard bill. If the egg didn’t break, it could only be because the bird had carefully exercised restraint. Why? Did it know it would break the egg if it were handled like other objects? Did it know that breaking the egg would cause the contents to leak and be lost? After dropping the whole egg into the begging young’s open throat, the egg would have been crushed had the young swallowed.
My first impulse was to drop the egg int
o the mouth of one of the young birds, because there seemed little else to be done with it. As nourishment, the tiny egg had minuscule value; as an object of beauty, much. I hesitated.
I rolled the egg in my fingers, astonished by the purity of the light blue color and the symmetry of its shape. I found myself handling it delicately, as though afraid it might crack at my touch. This was more than just a beautiful object. Unlike all the other parts of birds, mammals, frogs, or snakes these young ravens might have eaten, this morsel still had a possible future. It could become a living bird. It had the potential to become a robin with a red breast who sings a beautifully melodious song at dawn. This egg was like the underdog kid who has beaten all the odds. The audience is cheering for him or her to continue, because he or she represents everyone’s hope. I gently placed the egg into my mouth, cradled it on my tongue, and took it down with me to find a robin’s nest and foster parents. Meanwhile, I was pleased with the results of my pipe cleaner study. It had given me one more little detail that would help to tie the raven’s sharing behavior that I had worked on for so many years into a more coherent picture.
Raven carrying three robin’s eggs (one in throat pouch).
Note: In 1998 I mastered the ascent to the cliff nest by my home in Vermont, and I repeated the ringing experiment on the three pinfeathered young in that nest. On the first three ringing episodes, spanning 16 hours, I retrieved four boluses of moistened white bread (40 grams), one bolus of pink (calf?) meat (20 grams), and two boluses of not-so-very-fresh liver (45 grams). After that I retrieved nothing in three days (total of 17 hours) that the young continued to be ringed with the pipe cleaners. Nevertheless, they had been fed; they had gained normal weight and never showed signs of hunger. I presume that the parents caught on to what was happening. They had probably devised a new way of feeding (tiny bits rather than boluses?), and I conclude that my graduate advisors had been right; perhaps one should indeed not try to study an animal cleverer than oneself.
Mind of the Raven: Investigations and Adventures With Wolf-Birds Page 8
