Environment Panama , Panamá, Monday, April 22 of 2019, 08:47

Where science meets music: a banjo player listens for the songs of katydids

What do playing the banjo and recording katydids have in common?

STRI/DICYT A Google-search on ‘Sharon Martinson’, comes up with a curly-haired woman with a banjo, named Wyoming’s Performer of the Year. Keep scrolling down, and you come to a Dartmouth College visiting scholar, a scientist studying katydids in Panama with the Smithsonian Tropical Research Institute (STRI). Both of these individuals are the same person.


For years, Sharon’s life revolved around science. She had recently completed a postdoctoral fellowship at the University of California in Santa Cruz, looking at the impact of climate change on forest-insect interactions, when she decided to take a break and embark on a musical journey. By the end of the year, she had a band, The Littlest Birds, released an album, and went on their first tour.


But after two years of touring and spending her winters on the Baja California coast, Sharon started feeling that something was amiss. She felt like she needed to gather data and analyze it: any data. Taking advantage of her surroundings, she began to measure and record the seed set, stalk growth and flowering rates of every agave plant on her property.


“My brain craved science, like an addict”, Martinson recalls, while sitting in the middle of the forest at the Smithsonian’s Barro Colorado Island (BCI) research station in Panama, with a banjo on her lap, ticks crawling up her arms.

After that experience, she never let music and science drift apart again. She went back to studying insects in the forest. Her experiences in the field, in turn, inspired songwriting. A few months of science were followed by a few months on tour. By finding a way to balance both occupations she was able to stay balanced herself.


“Having a brain that behaves creatively helps you come up with more interesting science questions. Being a musician has also made me a better listener,” she believes. “I have a hard time not hearing something in the forest.”


Coincidentally or not, she was invited by Dartmouth researcher Hannah ter Hofstede to join a project at STRI that requires her to listen. It focuses on sound, in particular, the songs of male katydids. Although many katydid songs are effectively silent to humans –because most are ultrasonic and extremely short– they are attractive to female katydids.


Since these insects are most active when its dark, Sharon evolved into a nocturnal creature. Twice per night –a few hours before midnight and a few hours before dawn– she approaches the lights near buildings and along trails on the island. This is where katydids are most likely to be found. It seems like a lonely, humid, walk. It is late and most resident scientists are in bed, yet the symphony of nocturnal forest dwellers creates the illusion of having company every step of the way.


Sharon carries a flashlight in one hand and a plastic bag full of used Ziplocs in the other. She is an expert in grabbing katydids before they have had a chance to react. And after a quick look, she can usually identify the species, as well as any peculiar trait –"this one is particularly bitey or that one is a jumper"–, that probably only a handful of other people in the world know. By the end of the night, she may end up with one or up to 60 katydids, each stored away in its own bag, marked with the date, time and location of capture. The average number varies based on the phases of the moon. With a full moon, the night is bright and katydids are less attracted to the artificial lighting.

They are also quite diverse. In four years of visiting the island every dry season, she has captured over 120 species, each with a different mating call. To develop a database of katydid songs for BCI –which aims to help identify each species by their call– she places the males in tiny recording booths that capture their ultrasonic calls for 24 hours. These recordings can then be slowed down, allowing the calls to be perceived by human ears.


Aside from these recordings in isolation, the project involves soundscape recordings in the canopy. Comparing the katydid calling behavior in nature, when bat predators are present, to that in the recording booth, can shed light onto the distribution of katydids in the forest and their natural calling rate.


Their cages have accelerometers too, which keep track of their trembling, an alternative means of communication for some species. By sending vibrations through the branches, they can elude predators capable of hearing ultrasound, such as bats.


“As a scientist, my job is observing things, so my music is very much influenced by what I see. I have a song I’m working on that has been inspired by what I fondly call ‘babydids’. Katydids, the day they hatch from their eggs, are the cutest insect you’ll ever see,” she confesses, before performing one of her hits in the forest: Four-Wheel Drive, an upbeat song about going back home.


After striking the last chord, she picks up an ant from her banjo and quickly identifies it as a Crematogaster. “It’s amazing how many insects come when I play the banjo,” she says with a smile, caressing the instrument she has played professionally for the last 12 years, the instrument her grandfather used to play too.


With her tunes, mostly traditional Americana music, Sharon has travelled around the United States and to other countries. She has also toured nursing homes, prisons, schools and soup kitchens, with her non-profit called “Play it Forward”, which takes music to underserved populations. Eventually, she would like to play music in refugee camps around the world.


In doing so, she feels proud to be carrying on some of the historical banjo tradition: an instrument that originated on the West Coast of Africa and was brought to the New World by slaves. In her fourth album, which is about to be released, she plays an old gourd banjo, a replica from the time.


“They worked together in the plantations, yet didn’t share a common language, history or culture. All they shared was their own version of this instrument they all played. It was their way to communicate without words,” Sharon explains. “One of their tunes was meant to alert about a break in the patrol, so that they could run and escape the plantation. It communicated the hope of freedom.”


Just like humans have a long history of using music and sounds to express ideas, hopes or emotions, katydids sing to reach out to mates in the dark forest, while trying to avoid predation. And for Sharon, their ultrasonic songs are her only way of understanding their world.


“In some ways, I’m just like a katydid. Because if you listen to my songs you can also figure out what’s going on in my life,” she laughs.


Yet the more she learns about these insects, the more she realizes she knows very little about them. Where they live, what they eat, how abundant each species is, how long they live, what their individual song is and where they sing, are just a few of the questions yet to be resolved.


“Every time we think we’ve uncovered something about katydids, we realize there’s like six more things we don’t know. It’s like that T.S. Elliot poem: ‘We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time.’ But so much that is still unknown about this entire community, we can learn about by just listening carefully,” she concludes, as she fiddles with her banjo, ready to resume her concert in the forest.