There’s an old summer camp myth about a common spider: the most venomous in the world, with fangs too small to bite you.
Except that all of that is wrong, and the truth is even better.
Enter, on tall spidey stilts, Daddy longlegs. Known as “harvestmen” to their fans. Found on 6 continents, they are universal and abundant. Their little legs scurried around before the dinosaurs, and we’ve been ignoring them. You probably have one outside your window right now. They are not spiders, but a separate, subgroup of arachnids (a group of animals which include spiders). They aren’t blessed with venom or fangs, but with other powers instead. The magic of tiny, overlooked harvestmen is just beginning to unravel.
“Ok… Trial 3, number 86… Jerry, Elaine, George …” Ignacio Escalante, from the University of California Berkeley, is getting his PhD studying the leggy harvestmen.
He named all of today’s study specimens after characters from “Seinfeld.” He says sometimes they pick up Seinfeld personality traits. If they do, you could expect a wacky Kramer anecdote to show up somewhere…
Harvestmen are able to detach their legs, to avoid being eaten. Nothing like leaving your foot in the big bad wolf’s mouth: an almost clean getaway. Escalante is studying how limb loss affects harvestmen’s (Prionostemma sp.) movement and speed. To do this, he travels to La Selva Biological Field Station in Costa Rica, his home country. Here he videotapes harvestmen walking, starting with the full set of eight legs but working with some who have only six left. Using delicate tweezers, he squeezes a harvestmen leg. Right on cue, the tiny acrobat is able to pop off the assaulted limb. Thus, he escapes his perceived threat like a boss. A defense system like a Lego set. Easy to disassemble. Limb loss may slow them down temporarily, and Escalante wonders how long it will take them to get back to cruising speed. Because shedding legs is part of their survival strategy, do the harvestmen notice the loss? Is it possible for an organism to lose body parts and not even slow down?
“Oh no!” A harvestman high-jumps across the counter. Escalante laughs gently as he searches for the escape artist. Behind him, Kramer the Harvestman tiptoes onto an electrical cord. “Damn Kramer! I knew Kramer would do something like that. Ok, now you only have five legs…” Unfortunately, Kramer lost a leg in his jailbreak, which will disqualify him from the trials. Like his wild-haired “Seinfeld” namesake, he’s gotten himself into big trouble, although this one might earn him an early retirement. Escalante’s easy-going demeanor flickers out to genuine disappointment. Is he sad about Kramer’s lost leg, or the lost data point in his trial?
Escalante’s harvestmen live on the lab counter, neatly stacked in clear, take-out food containers. Each one gets a daily meal of fruit and Gati cat food. In the corner, he has arranged an elaborate miniature film studio: square spotlights, a white backdrop, and a GoPro camera. He adeptly plucks up each harvestmen and places it on an “X” stage left. Once released, this pencil eraser with legs sprints across the stage in front of the camera. Escalante will later analyze the video footage to study the speed and biomechanics of harvestmen running with different numbers of legs at various time intervals. He hopes future science might use his research to inform prosthetics and bioengineering, although the implications are still unknown.
“Sometimes they’re just like children. You have to feed them, take care of them, go look for them in the forest.” Escalante gestures to his city of 40 harvestmen. (Last night, while out in the rainforest, Escalante encountered a large fer de lance, a venomous snake. “That was kind of a bummer,” he says, “because I’m always grabbing daddy longlegs everywhere, and once I see this snake that can kill me, I’m like, okay, I should be more careful.”) Escalante is in his late 20’s, with long black hair pulled back from his face. There might be a tiny piece of cat food in his curls. He’s sporting a short Count of Monte Cristo goatee, a shoulder bag with a swinging water bottle, and a nonchalance about rainforest dangers. “I just want people to know the harvestmen’s story.”
“The way science is, we want to study many animals in a broad context and write for broad journals, but at the same time, you just want to play with animals all day and be amazed by their biology,” he says. Escalante wonders if Latin American scientists have a different attitude about research than North American ones. Moving from Costa Rica to California puts him in a good position to compare. The training he received early on in Costa Rica emphasized understanding the animal. He describes it as a romantic notion: science for the sake of knowledge, pure joy of discovery. The North American training emphasizes global or historical contexts. For example, Escalante says in Costa Rica he tells people he studies harvestmen, but in the United States he would say he studies behavioral ecology. The culture of scientists differs with location, and to be sure, this affects the kinds of science that get funded. Which is better? Escalante defers that they’re both valuable in their own right.
After today’s last set of lab trials, Escalante must head back to the forest for a late afternoon collection trip. Everything on your wildlife bingo card can be ticked off here: two-toed sloths, toucans, and even “cotton-ball” bats, which weren’t on your list but are now. The balmy, palmy atmosphere is loud with monkeys, mosquitoes, and God-knows-what venomous fanged monsters campers dream up. Escalante walks down the forest trail, hunting harvestmen. The sound and the foliage crowd around him. He steps off the path, instantly dwarfed by strangler fig roots. He nabs the leggy speed demons, chasing them around the tree. Gingerly holding one, he explains that their secreted toxin works as a chemical shield against predators. As he does, two surprisingly white drops of liquid appear on its body. It smells acrid and unappetizing. Here you discover a clue to the origin of the summer-camp myth.
No venom, but instead a stinky oozing toxin. (Although who would want to smell it? Scientists?) No tiny fangs, but small, claw-like “pedipalps” for grabbing things. They’re not strong enough to break human skin, although maybe not for lack of trying. The lesser-known details are just as fun: pop-off legs and cat food snacks. A struggle to explain science and nature across cultural divides. Kids will tell appalling stuff around a campfire, but take comfort knowing there will always be scientists collecting stories even wilder than we can imagine.