In a parking lot in a secret location outside St. Louis, Becky Hansis-O’Neill and her team prepared to search for Missouri’s largest native spider.
They set off into the woods, hiking toward the spider’s home. Right away, a member of the party ambled face-first into a huge, elaborate web, home of an Orb Weaver — nowhere near the size of the spider they were looking for.
They continued their search, climbing over a fallen tree and walking into the sunny, desert-like glade habitat where the object of their study lives. Hansis-O’Neill put on gloves and began to lift big, flat rocks.
Under one, a spindly legged black spider with a red mark on its back was waiting.
“Ooh, an old wasp’s nest with a black widow on it!” Hansis-O’Neill said excitedly.
But that spider was too small.
On a plant nearby, another spider with a red abdomen sat watching the group. A “super smart” jumping spider, according to Hansis-O’Neill, but not what she was searching for. She went back to lifting up rocks.
Finally, Hansis-O’Neill found it: Missouri’s biggest spider — a giant, hairy tarantula.
And actually, another large spider that looked tiny in comparison.
“Is that a wolf spider right there?” asked research assistant Meagan Thompson.
“Yeah, she's living with a wolf spider,” Hansis-O’Neill said. “Oh, we'll need to write that down in the data.”
Next to the wolf spider, a few fuzzy tarantula feet were barely visible, poking out of a hole in the ground.
Missouri’s tarantulas
Missouri’s native tarantulas are known by their scientific name, aphonopelma hentzi, or their common name, the Texas brown tarantula. They have brown, black and gray hair all over their body and are about the size of an apple or orange.
When Hansis-O’Neill moved to Missouri to study at the University of Missouri-St. Louis, she wanted to learn more about their behavior, but soon found out there were bigger questions that needed answers.
“I was hoping to actually collect a couple tarantulas for my research,” Hansis-O’Neill said. “The Department of Conservation said, ‘Well, we don't have any idea how their populations are doing.’ And I said: ‘I'm not doing anything this summer. Can I go count them?’”
Four years later, Hansis-O’Neill is a Ph.D. candidate and has spent her summers looking under rocks in Missouri’s glade ecosystems to get an idea of the status of this species locally.
To study the tarantulas, Hansis-O’Neill and her team of UMSL students and recent graduates use an app to track the tarantulas’ locations. They tag the spiders to give them unique numbers, measure them and record their heart rates.
Over the years, Hansis-O’Neill has learned a lot about this population of tarantulas.
“We know a bit about their seasonality, when they come out, when they go to bed, when they have babies,” she said. “We've also learned that here in Missouri, their populations are not very dense compared to other places where they live, like in Texas and Colorado.”
Missouri is at the far northeast edge of the range for brown tarantulas, so the population is more spread out and fragmented.
“This isn't, like, the tarantula metropolis,” Hansis-O’Neill said.
Hansis-O’Neill doesn’t necessarily think that is cause for concern, but she hopes to soon know if the lower numbers are an indication that extra conservation efforts are needed to support the population.
“I think I need to do a lot more math to figure out if they're OK, and that's going to be part of my Ph.D. research,” she said. “I think we shouldn't expect to have really high populations here, but … it would be very easy for someone to go to a small glade and collect enough adults that the breeding population is just ruined.”
There’s good reason to worry about poachers ruining a population. It’s illegal to collect tarantulas from public land in Missouri, but in the glade, Hansis-O’Neill pointed out lots of evidence that people had been there looking under rocks.
Thompson, the research assistant, first got involved with tarantula research after coming across the illegal pet trade.
“It really disturbed me, especially being in this career where conservation is my main goal,” Thompson said. “Once I saw that we had the opportunity to work with tarantulas and conserve them in our own backyard here in Missouri, I really wanted to become a part of that.”
Docile cupcakes
Using a stick, Hansis-O’Neill coaxed the tarantula out of its burrow to collect data.
“This spider looks so healthy and colorful,” Hansis-O’Neill said.
The spider tried to look tough, raising two front legs up to look even bigger than she is, and Hansis-O’Neill cooed as she addressed it: “Oh yeah, give me the threat pose.”
Eventually the tarantula put her arms down and tried another defense mechanism.
“Often what they do as their first defense is they just cover their face,” Hansis-O’Neill said. “It's not very effective.”
While tarantulas do have venom, their bite is not particularly dangerous for humans. Hansis-O’Neill compared it to a bee sting.
Instead, the team worries about the danger humans pose to the tarantulas. Even by picking up rocks in the glades to look for them, humans can permanently damage habitat, throwing off the humidity and the temperature of the burrows. That’s why the team gets special permits and takes care as they conduct their study.
“It's really important that their numbers stay up in the wild,” Thompson said. “That's what we're hoping to preserve here.”
Preserving their habitat is also important. In glades, the Missouri Department of Conservation conducts managed burns to keep the right mix of plants in the delicate ecosystems.
Hansis-O’Neill has surveyed sites before and after controlled burns and found that the spiders still live there afterward. She thinks this is likely because the spiders evolved alongside natural fires, so they are adapted to it. The Department of Conservation’s burns also happen in the winter, when the spiders are hidden away and essentially hibernating.
Next to her home, the team cleaned the tarantula and glued a tag to her, dubbing her “white 67.” They also measured her and her burrow, where they found one of their old tags, meaning she was a recapture and hadn’t been scared off by her last encounter with humans.
“They're very docile,” said Hansis-O’Neill. “We don't even have to restrain them when we take the measurements and put little tags on them, so they're cupcakes.”
The UMSL tarantula team appreciates that Halloween is a holiday that celebrates animals that can be hard to love.
“Don't be afraid of the spooky, creepy crawlies that are around our local areas,” Thompson said. “They're here just doing a job and existing, and just because they're here and we may fear them doesn't necessarily mean that they don't have an important part in our ecosystem.”
Hansis-O’Neill agreed.
“They’re spooky and they’re fun, but they’re not dangerous.”
