I could see the five-year-olds wiggling in their circle-spots as they struggled to keep their guesses in their heads. Two cloth bags containing natural objects were making their way around the circle, and I smiled at the puzzled looks on their faces when they felt the hard, scaly surface of a beaver tail. The second bag contained a duck wing. It sparked more recognition and more secret-keeping challenges as they recognized the feel of feathers.
Cable Natural History Museum naturalists visits eight local school districts in Northwest Wisconsin three times each year for our MuseumMobile program. The kindergarten lessons are some of my favorites. I recently brought the tub of goodies to my niece and nephew’s classrooms in Iowa, too. We talk about using our senses to explore nature, and listen to lots of the kids’ stories about the deer my dad shot, or the wolf my brother saw, or the beaver that slapped its tail at me. In kindergarten, stories are king.
My favorite story comes when I open up a plastic sugar shaker they’ve been rattling around to test their sense of hearing. Into my hand roll three dried goldenrod galls. Usually the faces of at least one or two kids light up in recognition. Yes, they’ve seen that in the field behind their house, or on a walk in Grandma’s yard.
“Once upon a time in June,” I begin, “a fly landed on the stem of a goldenrod flower and laid an egg. The little tiny caterpillar hatched, and started chewing its way into the stem. As it chewed, the spit in its mouth asked the goldenrod plant to grow a house around it. That’s what this is: the goldenrod gall…the caterpillar’s house. The caterpillar lived in the house all winter long; even freezing solid! You can see his bedroom, here in the gall I cut open. Then in spring, the caterpillar makes a chrysalis, just like a butterfly, and comes out as a fly. That fly will find another goldenrod plant and lay another egg.”
It’s fun how even the most squirmy kids will sit still—mouths slightly open—as they become transfixed by a story. Robin Wall Kimmerer, author of Braiding Sweetgrass, speaks eloquently about the role of stories in science: “Our stories from the oldest days tell about the time when all beings shared a common language – thrushes, trees, mosses, and humans. But the language has been long forgotten. So we learn each other’s stories by looking, by watching each other’s way of living.” Science is one method we can use to “watch each other’s way of living” and discover the stories of other beings, now that we no longer share a common language.
Science has certainly added detail to the story of goldenrod galls. And Bernd Heinrich is an excellent example of a scientific storyteller. In his book, Winter World, he explains that the gall fly larvae react to cold fall weather by producing glycerol (an alcohol) and sorbitol (a sugar) that act as antifreeze. The colder the weather, the more antifreeze the larvae produce. In addition, northern larvae, who expect to encounter more severe temperatures, cause themselves to freeze solid by releasing a protein into their blood that provides nucleation sites for ice crystals. The benefit of this is that the larvae avoid supercooling and instant, deadly, freezing.
Instead, as the protein-enriched larvae cool slowly in milder temperatures, the intercellular liquid freezes first, concentrates sugars in little pockets, and pulls more water out of the cells. The cells become so dehydrated that few damaging ice crystals can form inside them.
Science is amazing at telling stories like sugar-filled freezing bugs and survival against all odds. I feel it’s my job to re-tell those stories to as many humans in as many ways as possible. Maybe one of those intently listening kindergarteners will grow up to be a story-discovering scientist.
After the lesson, as the kids lined up for lunch, I heard a small voice by my side. “Can I give you a hug?” asked the little girl with the glasses. It doesn’t take a scientist to discover that she, too, has some concentrated sweetness.
The larvae of goldenrod gall flies force the plant to grow a house around them. There they spend the winter, unless a bird eats them or a kid dissects them. Photo by Emily Stone.