The Great Animal Orchestra

by Krause, Bernie

  But biophonies are distinct not only from place to place—time plays a very important role as well. Although there is always some kind of performance occurring wherever there is wildlife, in places with a clear period of day and night a dynamic biophonic energy is at hand. My wife and I live just north of the thirty-eighth parallel in the Northern Hemisphere. Our biome is made up of a hilly, oak, chaparral landscape below a thousand feet, and we’re forty miles east of the Pacific Ocean. From late March to late October there is hardly any rain—although over the past fifteen years the climate has started to change. During a normal rainy season, we’ll get roughly thirty inches of precipitation. For several months a year—from March through mid-July—the biophony runs on a clear cycle: heavy at dawn (called the dawn chorus) and dusk (the evening chorus). By my estimate, on a scale of one to ten—with ten being the most active biophony we hear—the dawn chorus from just before sunrise to about a half hour after is a ten. The evening chorus, from about a half hour before sunset to just after the sun drops below the horizon, is about an eight. Biophonies that occur during the day, in between the dawn and evening choruses, vary anywhere from a five to a six. Evenings after dusk, given the local tree-frog and insect mix, float between a four and a five, while the time between midnight and first light usually hovers consistently around a very relaxing and soft-textured three—the best sound for sleeping.

  Over the course of the summer, especially toward the beginning of August, the birds become very quiet, although they’re still around, and the crickets become the dominant sound sources during the evenings and night—at times so intense that they’re seemingly as loud as the dawn choruses of spring. These cricket choruses will last well into December, when the rains begin in earnest. Then they will cross-fade into the amazingly loud voices of the tiny Pacific tree frogs, signaling that it is mid-and late winter and anticipating the first bird activity of the early spring, when the cycle begins again.

  Every biome on the planet expresses itself with these types of specific bioacoustic sequences and patterns, whether urban, rural, or completely natural. Climate change may be one reason that biophonic patterns are rapidly beginning to transform—some much more abruptly than many biologists and naturalists expected. There also may be other factors, such as early USGS indicators of polar magnetic shifting (as differentiated from magnetic field reversal). Currently, at the time of this writing, the poles are reported to be moving at a rate of almost eight-tenths of a mile a week. The consequences are not immediately clear, although if true this type of phenomenon alone may already be affecting some migration patterns. In locations that I’ve revisited through out the world over the past several decades, the troubling muted result of human impact has been evident time and time again.

  There have been acute and obvious changes in North America, notably in the areas where I have returned and recorded more than once over the past four decades. During the 1980s, a favorite spot of mine to record was a quiet but accessible site near Jackson Hole, Wyoming. From the early part of the decade, when I began visiting, well into the 1990s, the biophony remained fairly constant—the bird mix included warbling vireos, yellow warblers, white-crowned sparrows, Wilson’s warblers, house wrens, and dusky flycatchers. By 2009, when I returned to sample the site after a lapse of five years, the soundscape had radically shifted. Springtime was occurring weeks earlier on average and the bird mix was now made up of hermit thrushes, Swainson’s thrushes, cowbirds, grosbeaks, yellow-rumped warblers, dark-eyed juncos, chipping sparrows, and white-crowned sparrows—a very different combination. Exactly what these changes signify, we have no idea. But they correlate with reports from bird biologists throughout the United States, who have noticed similar changes elsewhere. Colleagues working in locations as far-reaching as Africa and Southeast Alaska have mentioned recent changes in avian, mammal, and insect combinations, which they’ve noted in biomes such as the accelerated melting glaciers on Mt. Kilimanjaro and in Glacier Bay, and in and around coral reefs.

  We are discovering that the governing features of a biome’s biodiversity are delicately balanced to the extreme. The biophonies of healthy habitats generally fall within a certain expected scope, meaning that given the range of the region’s seasonal climate and the relative stability of the landscape, organisms that typically thrive there should reflect expected numbers of species and total population. What we have noticed is this: Whenever a biophony is coherent, or what some biologists consider “within a range of dynamic equilibrium,” the acoustic spectrograms generated from recordings illustrate remarkable discrimination between all of the contributing voices. On the other hand, when a biome is compromised, spectrograms will lose both density and diversity, along with the clear bandwidth discrimination among voices that is otherwise visible in nonstressed-habitat graphic displays. Biophonies from stressed, endangered, or altered biomes tend to show little organizational structure.

  When habitat alteration occurs, vocal critters have to readjust. I’ve noticed that some may disappear, leaving gaps in the acoustic fabric. Those that remain have to modify their voices to accommodate changes in the acoustic properties of the landscape, which may have been altered by logging, fire, floods, insect infestation, or other shifts in the nonbiotic components of the habitat. All of these variations mean that the natural communication system evolved within a soundscape breaks down and becomes chaotic until each creature’s voice once again finds a place in the chorus. This could take weeks, months, or, in some cases, even years. At Lincoln Meadow the biophony at the last visit (2009) remains relatively quiet, with very light density and notably altered diversity, even after almost a quarter of a century of supposed recovery.

  Listening closely to the soundscapes of wild habitats, you can immediately hear sound coming from three basic sources: (1) nonbiological natural sounds—the geophony; (2) sounds originating from nonhuman, nondomestic biological sources—the biophony; and (3) human-generated sound—anthrophony— where it intrudes and, in a few cases, blends. As recently as the turn of the millennium, the field of bioacoustics was still focused on the notion that there was nothing much to be found beyond the single-voice abstraction of individual organisms. It would never have occurred to most biologists to evaluate the health of an entire biome by listening to and studying in greater detail the total acoustic community. But, as my archive was beginning to uncover, there are multiple layers of consequence mixed into that collective voice.

  Within soundscapes are manifold narratives—encoded stories that expose long-held secrets, what Samuel Coleridge once referred to as the “mighty alphabet of the universe.” And as Loren Eiseley reminds us, we were originally readers long before we were writers, and for me the biophony has always held the most exciting surprises.

  CHAPTER FOUR

  Biophony: The

  Proto-Orchestra

  In the early 1980s, soon after I received my doctorate, a friend working in the Exhibit Design Department of the California Academy of Sciences called to ask if I’d be interested in collaborating on the re-creation of an African water hole that he was crafting. In the field of animal recording, this request was unusual, since most exhibit models were the then thirty-year-old push-a-button/hear-a-sound types. In this case, the designer had in mind a much more holistic approach to the overall presentation—one very different from the common single-species list. Kevin O’Farrell was a design visionary who imagined a water-hole soundscape that featured a whole host of animals, removed the glass separating the visitors from the creatures, and brought the diorama itself out into the hall—a radical shift from the museum-design paradigms that had been in place for more than a century. Running for fifteen minutes, the audio performance would cycle through the events that occur at typical water-hole sites over an entire twenty-four hour period. The sound track would be synchronized to lighting that would match the times of day represented.

  O’Farrell’s request meant planning and executing a more comprehensive field approach than I had ever consi
dered previously. While I had worked in the wild on shorter trips, both on land and in water, this was the first concentrated, long-term, faraway field adventure I had ever undertaken. After experimenting for more than a month with various types of gear—there was absolutely no one to consult other than a few film sound recordists who were unfamiliar with the specifics of recording stereo natural soundscapes—I finally decided on a set of stereo mics and a portable recorder that was more frequently used for recording indoor orchestral performances. Through friends in Kenya, I was introduced to a patient and informed guide, one who needed to arrange the trip to the special requirements of capturing soundscapes. It was to be the first full set of round-the-clock natural soundscapes in my archive—or any other that I knew of—aimed at collecting not only dawn, daytime, dusk, and evening choruses but also single species’ recordings.

  About a week into the trip and several hours after midnight at Governors’ Camp in the Masai Mara, I set up my gear and began to collect extremely rich natural sound from a nearby old-growth forest—one typical of what early humans might have encountered. After the camp’s generators had been shut down and the staff retired, it finally became quiet, except for the forest ambience itself. If sound was going to be this glorious everywhere in the Mara, I realized, I needed to conserve the limited supply of tape I had brought and record at half speed, so that one reel would last for forty-five minutes instead of the usual twenty-two, even if I was at risk of losing a small degree of quality. The magnificence of creature voices was enhanced, no doubt, by my total exhaustion. I felt like I was hallucinating. The sonorities shifted like waves of Möbius strips wafting by in the still evening air, anchored by the throbbing rhythm of the insects.

  My mics were mounted on a tripod just outside my tent by the river, where I had settled into my sleeping bag wearing a set of earphones. I didn’t care if my batteries went dead—I was hoping to lull myself to sleep with the gentle predawn atmosphere as background. It was in that semifloating state—that transition between the blissful suspension of awareness and the depths of total unconsciousness—that I first encountered the transparent weave of creature voices not only as a choir but as a cohesive sonic event. No longer a cacophony, it became a partitioned collection of vocal organisms—a highly orchestrated acoustic arrangement of insects, spotted hyenas, eagle-owls, African wood-owls, elephants, tree hyrax, distant lions, and several knots of tree frogs and toads. Every distinct voice seemed to fit within its own acoustic bandwidth—each one so carefully placed that it reminded me of Mozart’s elegantly structured Symphony no. 41 in C Major, K. 551. Woody Allen once remarked that the Forty-first proved the existence of God. That night, listening to the most vivid soundscape experience I’d had to that moment, I came as close as I would ever come to said revelation.

  In planning my first long-range biophonic assignment, I had anticipated recording perhaps fifteen hours over the course of two weeks. At the normal high speed of the tape machine, that would have meant carrying forty-five reels weighing a pound apiece in addition to three sets of twelve D-cell batteries. I had already decided to record at half speed, but it turned out that I could have used a hundred more reels if I’d been able to manage the additional weight of batteries and packing boxes. On the flight home, for as long as my remaining power supply held out, I impatiently began reviewing the breathtaking range of material collected during my time on the ground in Kenya. Since so much in the field depends on luck, I couldn’t believe the quality of the recordings I had captured, but at the same time I was disappointed that I hadn’t had time to record more. My depression was tempered by the hope that what I heard could actually be visualized and that I might someday return, now that I knew what to expect.

  When I arrived back at the lab in San Francisco, one of my first tasks was to transform the recorded samples into spectrograms—graphic displays of sound showing time and frequency, where time is represented from left to right on the x-axis, and frequency from low to high on the y-axis. When I listened to playbacks of my audiotapes and looked at the related spectrograms, my heart began to race with anticipation.

  Just as black-and-white photographic images gradually appear on photo paper during the development process, unmistakably clear patterns materialized from the printer representing the audio sequences I had recorded. As the images slowly emerged, the überstructure of the soundscape plainly showed distinctive shapes not unlike modern forms of musical notation—the bat was vocalizing in the highest frequency range, insects in the middle, hyrax and hyenas a bit lower, and elephants down at the lowest end of the biophonic score. And each representation was unique. The bat was echolocating, sending out brief, high-frequency pulses of sound shown as two sharp lines in the upper-right-hand side of Figure 5. The hyrax, the “soloist” of the moment, sounded like a windup toy—a series of progressively slower grinding sounds followed by high, breathless screams. The tracery of its voice is illustrated midway across the page, beginning at the left-hand side. Once it completes a phrase, the hyrax repeats its vocalization all over again. A distant hyena found a location in the forest that resonated like an echo chamber—probably a water hole—and its voice reverberated, hanging over the soundscape in a different way than the other animals’.

  Before I printed those first spectrograms on my return from Kenya, I had considered natural sound to be a chaotic random expression. The reductionist single-species method we had all been taught had us coaxing each animal voice out of its coherent context and trying to derive meaning from the sounds we abstracted from the natural world. Most of the international bioacoustic community felt the same way, as the great bird and mammal sound collections at repositories such as the British Library of Wildlife Sounds and the Macaulay Library at the Cornell Lab of Ornithology attested until very recently. But after Kenya, as I began to look more closely and found new acoustic software tools to work with, the patterns suggesting musical structures in the natural soundscape became too obvious to dismiss.

  Figure 5. Masai Mara predawn example.

  Based on the recordings from that first commission, no matter which 1983 Kenyan habitat I looked at or what times of day or night the recordings were made, niche discrimination plainly appeared on the page. Insects set the stage for every other sound, some by establishing uninterrupted drones that sounded continuously throughout each day and night, others by setting up rhythm patterns. Every bird species appeared to mark out its own acoustic turf. Mammals filled other niches, as did reptiles and amphibians. Before that night in the Mara, it had all sounded like anarchy to my ears. Now, for the first time, certain patterns within the structure became clear.

  When I saw the first soundscape spectrographic images reproduced from rather primitive gear in the 1980s, I was reminded of William Turner’s late seascapes. The early-nineteenth-century English Romantic artist’s impressions only half suggested detail, teasing and drawing us into his mystical reality and letting our minds fill in the otherwise evocative representations. Even then I dared to think of the spectrograms as contemporary graphic musical scores—not that different from those written by the Canadian composer R. Murray Schafer, for example (Figure 6).

  Discovering an ordered soundscape in Africa was astounding and never expected. I felt how amateur astronomers must feel when uncovering a major new galaxy or planet, upstaging the “experts.” Ecstatic and armed with several dozen recordings, spectrograms, and other material for support, I couldn’t wait to share my findings with my colleagues at the California Academy. Unfortunately my idea of the acoustic collective was dismissed out of hand. Alas, this wasn’t a collegial nest of astronomers, and no one looked too deeply. My superiors made it clear that they had sent me to Africa on a mission to collect soundscapes for an exhibit, not to come up with new hypotheses. I was dismayed but not by any means dissuaded. I knew what I had heard and seen, and I felt the significance with certainty.

  Figure 6. Page 5 from the score of R. Murray Schafer’s “Snowforms,” a choral composition for child
ren (Arcana Editions, 1983, used with permission).

  Gradually the growing body of my work validated the idea that creatures vocalize in distinctive kinship to one another, particularly in older, more stable habitats. Every subtropical or tropical old-growth habitat I recorded confirmed the partitioning model. Colleagues such as Ken Norris at the University of California, Santa Cruz, who immediately saw the potential and encouraged more comprehensive research, helped the concept gain footing by arguing in its favor with mutual associates and having me present the thesis at various forums that he, too, attended.

  As my work garnered more support, I continued to investigate what was known of composition of natural soundscapes. Of course, regardless of the time it takes for academics to come around to an idea different from the ones they have invested in, it turns out that many human groups have likely understood how wild sound is layered since our ancestors first began to hunt and forage for food. The ability to correctly interpret the cues inherent in the biophony was as central to our survival as the cues we received from our other senses. Through the nuanced textures of natural soundscapes in the thickest vegetation, where sight lines were limited by density or darkness, we tracked prey, determined its location and direction of travel, and imitated sounds that had both practical and symbolic meaning. Forest-dwelling groups understood these signals and utilized them long before the last ice age receded. It was a time when natural soundscapes were “read” in much the same way that recipes are followed in cookbooks and routes traced on a road map.