Wild Life / earthworm

they're on the move

Hi, friends — this is issue #19 of my newsletter about animal encounters. I’m going low this week to an animal we all know well, the earthworm, specifically Lumbricus terrestris. There are some surprises in store. Even the simplest creatures have an enormous history. — AJP

One morning, a few years back, when all the neighborhood kids met at the school bus stop, three small girls huddled in a circle on the road. It had been rainy all week but was clear that morning, soft and gray. One of the girls, hair swept into a ponytail, crouched to the ground and picked up an earthworm.

The huddle burst into screams, and the girl flinched, releasing the worm straight up into the air over their heads. The trajectory was shockingly perpendicular. It was so strange that I felt everything shift into slow-motion, the way things do. The worm hit the apex of its journey maybe ten feet up and struck an elegant arabesque before falling back down between the girls, landing exactly where it had begun.

The bus arrived and all the kids ran over in a torrent of goodbyes, parents waving. The worm picked up where it had left off, inching its way across the pavement.

I think about this episode when the earthworms appear, in the dirt under my shovel, under my hands, across the roads on rainy days. It’s the end of March and the worms are on the move.

Recently I learned the big ones, the night crawlers (dew worms in Canada, lob worms in the UK), are invasive to North America. This rattled me, given that these worms are common in all the earth I’ve ever known. In fact, L. terrestris arrived with European colonists in the eighteenth century. Before then, much of North America had no worms at all. The last Ice Age, which sent glaciers creeping across the top half of the continent, rid the underlying earth of worms.

And so, ecosystems developed without them. Other invertebrates thrived in the leaf litter, which was packed in tight layers over decades. Smaller plants and hardwood trees retrieved nutrients from this system that supported fungal networks. And then, over time, these big earthworms (thanks to us) changed everything, chewing their way through the layers.

Known as a “keystone species,” earthworms have the capacity to remake ecosystems. They change the life around them, and they’re here to stay. So here are a few curious things to know: they breathe through their skin; they are simultaneous hermaphrodites that need their eggs to be fertilized by another worm’s sperm; they find each other, often at night, to mate (through slime tubes); they make cocoons and deposit them in new burrows; worms feel pain; if you cut a worm in two, the half with the head will survive; they don’t have eyes but can sense light and dark; they can’t hear and will not respond to the sound of a bassoon (this one courtesy of Charles Darwin).

To be honest, I’m a little overwhelmed by my new earthworm knowledge. They have only simple brains but clearly a very complex impact. I wonder, what must that worm have felt, ten feet in the air on that strange spring morning years ago?

The earth is mine.

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Earthworm links—

• Read about “global worming” in this very informative article by Julia Rosen at The Atlantic.

• Rather than watch videos of worms, let’s enjoy a worm’s eye view of seeds growing. [YouTube]

• But if you’re curious about worm burrows, here’s a short clip at Britannica.

• Darwin’s final book was The Formation of Vegetable Mould Through the Action of Worms, With Observations on Their Habits, published in 1881, a year before his death. It outsold On The Origin of Species, probably because of passages like this: “[Worms] took not the least notice of the shrill notes from a metal whistle, which was repeatedly sounded near them; nor did they of the deepest and loudest notes of a bassoon. They were indifferent to shouts, if care was taken to ensure that the breath did not strike them. When placed on a table close to the keys of a piano, which was played as loudly as possible, they remained perfectly quiet.” [Harvard Gazette]

Animal encounters in recent comments—

• An exuberant chipmunk chorus in Michigan! thanks to Lauren.

• On a sadder note: “There is so much drama in the lives of wolves, with and without our intervention. Takaya’s heartbreaking story really shows how much these animals mean to us, even as we pose a serious risk to their well-being.” Enormous thanks to Katharine for sharing this story, plus a great book recommendation, documentary, and mural—highly recommend.

Also—

• The Full Worm Moon is this Sunday … actually, “The Next Full Moon is the Worm, Crow, Crust, Sap, or Sugar Moon; the Pesach, Passover, or Paschal Moon; the Holi Festival Moon; Medin or Madin Poya; the Shab-e-Barat or Bara'at Night Moon; and (by some definitions) a Supermoon” — I love this, at NASA.

• I’m going to take next week off for Easter but may send a picture. Full newsletter will resume on April 9.

• I illustrated the book Florapedia, written by the lovely flower genius Carol Gracie. You can preorder it here in time for spring flowers. We worked on it last summer, and looking at flowers and corresponding with Carol was the best thing I could have done during the early days of the pandemic. It is a beautiful book and I’m very proud of it. Here’s a sneak peek:

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Thanks so much for reading and sharing with friends and family. You’ll be thinking about worms all day now. This newsletter is a small weekly adventure about the life around us. If you’ve read this far and haven’t subscribed, please do!