The Delights Of The Instant

The combative chirping and frenzied wing whirs of hummingbirds are unique to the Americas. But thirty million years ago, hummingbirds were European, as attested by fossils from Germany. This ancestral stock then colonized South America. The European hummingbirds went extinct, but in South America the birds found a congenial home and, in partnership with flowering plants, rapidly diversified. A taste for sugar may have stimulated the evolutionary flourishing of both hummingbirds and songbirds. Genetic changes to taste receptors happened early in the evolution of both groups, repurposing an umami receptor to taste sugar. Songbirds, hummingbirds, and parrots are all highly vocal, and many of them learn their songs and have vocal cultures. In the rich voices of birds, we hear the sweet gifts of flowers and sap. As we listen, we hear the legacy of chance events from millions of years ago. Had a different group of birds been blown to Asia from the north coast of New Guinea or wandered across the Bering land bridge to the Americas, bird soundscapes would have a very different geographic structure. Overlain on these quirks and accidents of history are millions of years of speciation and adaptation in each of the descendant populations. Combined, these are the stories of evolution’s creative manufactory of sonic diversity.

Under The Gun

These studies also reveal something about human senses and affinities. We have approximately one hundred times more genetic information available from birds than from insects, and so reconstructions of the avian past have wider and sturdier foundations than those of insects. What is missing is research funding and scientific attention. Birds are popular subjects of scientific study partly because they catch our eye. Bird colors entrance us, and their bodies are large enough for the sight of them to evoke the human imagination. Icarus flew on wings of feathers, not of insect exoskeleton. The Christian Holy Spirit descends as a dove, not a cicada. Birdsong more closely approximates the frequencies, timbres, and tempi of human speech and music, further linking them into our senses and thus our aesthetic affinities. Were insects as mellifluous and colorful as birds, we’d devote more attention to their study. Birds’ prominent roles as poetic, religious, and national symbols are a product of these particular tunings of human eyes and ears. If we communicated by ultrasound, as rats do, or by scent, as many salamanders do, we’d have rodents and newts on our coinage and in our sacred texts. Our sensory proclivities also spell doom for many bird species.

Loose Ends

One in five vertebrate animal species are captured and traded worldwide. Species with feathers and songs that please the human eye are especially popular. A few insect species are captured and kept, especially crickets in parts of Asia, but wildlife trade is an insignificant threat to most, unlike bird species whose evolutionary path led them to the unhappy end of being attractive to humans. Yet alongside peril is the power to provoke change. Human aesthetic responses prompt moral concern. A Robin Red breast in a Cage / Puts all Heaven in a Rage. Our senses lead to desires for both consumptive possession and protective care. Perhaps by appreciating the origins and fragility of the marvels that delight us we might tip our desires and actions toward the conservation of wild beauty? The sounds of Mount Scopus, Saint Catherines, and Crowdy Bay seem so ephemeral and light, dissipating as soon as they are made. Despite being fleeting, they are also layered records of history. Every voice carries the imprint of its clan’s origin and dispersal. A soundscape is therefore an accretion built over hundreds of millions of years. Alongside these delights of the instant is an invitation to hear the stories of evolution’s past.

A Sort of Homecoming

These legacies of animal movement and plate tectonics are often older than the ground under my feet. Saint Catherines Island is made of Pleistocene sand and more recent dune deposits, none older than fifty thousand years. The sounds atop these soils and stones are often tens or hundreds of millions of years older. Sound, made of breath and gone in an instant, can be older than stone. Listening to the animal voices around us, we hear the legacy of a sonic geology made of vibrations in air, diversified by plate tectonics and the ancient movements of animals across continents. Unlike stone, no durable physical substance carries sound’s many shapes through time. This sound was simple, just a string of whistled notes, seemingly unremarkable compared with the complexity and range of birds and insects that sang outside the caves. Yet the sound was revolutionary. In the moment of its creation, Earth’s generative powers leaped forward, powered by cultural evolution. Hunter’s breath animates the skeletons of prey. Millennia spent buried in dust and rubble have imbued a stain the color of pinewood. In a dark room, resting on black cloth in glass cases, the objects glow under gentle spotlights. I’m in the Blaubeuren Museum of Prehistory in southern Germany, gazing at flutes crafted nearly forty thousand years ago from bird wing bones and mammoth tusks. The flutes’ seeming fragility astonishes me. In preparation for this visit I’ve pored over technical papers and studied photographs. On paper, the objects look substantial, like sturdy bones familiar from a dinner plate or zoology lab. In their presence, though, I’m confounded by how old and delicate they appear. My body and emotions finally understand what my mind has tried to grasp. I’m in the presence of our species’ deep cultural roots. These objects are the first known physical evidence of human instrumental music. They are three times older than human agriculture. Two hundred and forty times older than the age of oil wells and gasoline. No other species makes musical instruments, although a few come close. Some tree crickets cut holes in leaves to amplify the trill of their wings, and mole crickets shape their burrows to act like trumpets. In both cases, the insects are amplifying existing voices, not creating new ones. Orangutans sometimes press leaves to their mouths to make kissing sounds, but they do not, as far as we know, reshape the leaf for this purpose.