When a friend and I were talking about the age of songs recently, he asked how old I thought the oldest known song was. I’m not usually good at music trivia, but I knew the answer to that one. I have listened to a recording of a song that was heard 165 million years ago, back when dinosaurs roamed the tree fern forests of the Jurassic. The original performer was a now-extinct katydid that created this sweet sound by rubbing the base of his forewings together.
The song was revived when the fossilized remains of this katydid were discovered, so well preserved that bioacoustic scientists were able to compare them with existing katydids and reconstruct its prehistoric love song. You can hear it too, ringing today through the jungles of cyberspace. Search for "Jurassic katydid song" or "Archaboilus musicus." You will find the sound familiar; not unlike the song of the fall field cricket with its low, sweet chirps.
If by song we mean a pleasing sound produced for the purpose of attracting a mate, which seems to be true of nearly all songs I can think of, the songs of the katydids and crickets, which make up the suborder Ensifera, must be among the earliest on the planet.
If you watch a cricket chirp, you will notice that he (as with birds, it is the males that sing and females that select their favorite singer) first raises his wings and then vibrates them together. Their songs probably began as visual signals to attract mates. The tree crickets raise their long forewings straight up and fan them out, making a heart-shaped display. Vibrating them would surely be even more alluring. An audible vibration would be more attractive still and would have the tremendous benefit of broadcasting a location and fitness message to potential mates some distance away.
The wings of male katydids and crickets developed according to the whims of females. While the tones and textures of the songs vary among species, the instruments are similar. At the base of one forewing is a ridged area, at the base of the other a thickened scraper. When the two are rubbed together -- music!
If a song is to work its magic, the intended must be able to hear it. Scientist believe that the ears of early musical insects evolved together with their music-making ability. The ears of katydids and crickets are located just below what would be knees on a vertebrate. If you look closely you can see them, openings the size and shape of the eye of a needle. These ears contain a tympanum that vibrates in response to sound waves. Before Ensiferans developed music, their legs had neural networks that were very sensitive to vibrations from the substrate, and they were therefore preadapted for developing sensitivity to vibrations borne by air.
Today, among the meadows and maples and between the feet of cows and moose, 31 katydid and cricket species make their music. Late summer is their season, from August until the onset of freezing weather. While many sing all day, the greatest diversity of song is heard in the few hours around sunset. Learning to recognize some of their calls can enhance appreciation for the soundscape of late summer.
Most of us recognize the "chirp, chirp, chirp" of field crickets. These are the black, shiny, round-headed crickets we picture when we picture "cricket." There are also four species of smaller, browner, fuzzier crickets -- the ground crickets. These are the hordes that scatter from your feet whenever you walk in the grass. While very difficult to distinguish by sight, their songs are easy to learn. The striped ground cricket makes a dry, buzzy sound: "Tzit ... tzit ... tzit," with a pause between each tzit. The tinkling ground cricket makes a series of clearly separated ringing notes: "tink Š tink Š tink." The Allard’s ground cricket makes a similar sound but strings the notes together too fast to count. The Carolina ground cricket speeds it up even more to make a slightly sputtery trill. If you pause right now and listen, you can probably hear some. These crickets provide the nearly constant background trill that can be heard in any grassy area, all day and all night. They will be the last insect singing in the fall.
On the night of the August full moon, I conducted a night class on singing insects. What a lovely night it was -- warm enough to make the insects giddy, and with enough moisture in the air to add a warm glow to the dusk sky. After spending time with recordings of the singing bugs, we strolled to the summit of Heifer Hill to enjoy the moonglow and look for and listen to the live musicians. A couple of intrepid bug hunters swept the grass with a net, the rest of us gathered around a sheet spread on the grass where they released their catch.
The most popular visual insect was a sword-bearing conehead. This gal was almost three inches long, bright green, and had white eyes and a pointy head. The male conehead song, a rapid mechanical ticking like a sewing machine, was one of the more abundant songs. We also saw gladiator meadow katydids, a woodland meadow katydid, and numerous ground crickets and field crickets. From the treetops at the forest edge we heard the familiar unmusical calls of the common true katydid: "Ka-tee-did!"
We had so much fun I decided to do it again in September. If you would like to become better acquainted with the local musicians with the deepest roots in the past, come to the Bonnyvale Environmental Education Center on Wednesday, Sept. 18, at 7 p.m. September is likely to be cooler and quieter, but there are bound to be some singers to entertain us.
Patti Smith is a naturalist at the Bonnyvale Environmental Education Center. The View from Heifer Hill, a feature on the nature of our region, appears in this space the first Saturday of each month. She welcomes your feedback at Patti@BEEC.org.