Spider Senses

“Anne explains spiders and their behaviors in ways that dispel fears,” says Amy Cheng Vollmer, Isaac H. Clothier Jr. Professor Emerita of Biology, for whom she also worked as a lab coordinator. “She sees every opportunity as a teachable moment to lend a balanced voice to the horror-movie stereotypes people have about spiders.”

Danielson-Francois’s scientific interest in spiders began at Swarthmore. In a class taught by Professor Emeritus of Biology Tim Williams ’64, she learned about the science of animal behavior. That inspired her to design her own behavioral experiments on a tiny twig-mimicking spider, the long-jawed orb weaver (Tetragnatha elongata), along Crum Creek.

Anne Danielson-Francois ’90 (right) shows then-research student Yevhen Drobot how to properly handle arachnids. Her research focuses mainly on spider reproduction.

Why those spiders?

“Peter Smallwood, a Haverford professor, had just given our campus a seminar on these spiders,” says Danielson-Francois. “And I thought, ‘Yes! I want to study those!’ He was kind enough to take me into the field and teach me about these spiders. Eventually, we published a paper together on their mating behavior.”

Today her research takes her from the jungles of Taiwan to the hardwood forests of southern Louisiana and Texas. Her research focuses mainly on spider reproduction, an esoteric field which could one day deliver insights into human fertility.

“I’m really interested in how their sperm gets activated,” she says. Male spiders deliver their sperm in tiny packets like billiard balls. Females store them and do something chemically to activate them. After the sperm compete, spider moms lay fertilized eggs.

Every year, Danielson-Francois leads her students on treks along the Rouge River in Michigan to collect the same species she found at Swarthmore. Because they mate repeatedly, they are easier for studying mating behavior than other species.

None of her students have ever been bitten by a spider. It’s a myth that all spiders are dangerous, according to the Centers for Disease Control and Prevention. Only two U.S. species, the brown recluse and black widow, have venom harmful to humans, and their bites are rare. In fact, spiders benefit humans by eating ants and other pests.

“I’m thrilled my spiders are doing their work, and they do it quietly out of the way. Once you can identify different species, your fear level goes down,” says Danielson-Francois. “I spend a long time taking students from terrified, to handling spiders with ease, and they become cheerleaders for arachnids.”

Her students feed the spiders for months and clean their containers, but Danielson-Francois gets more up-close-and-personal with the tiny twig-mimickers. To identify each mating partner, she removes them from their plastic drink cup homes topped with pantyhose lids and paints their legs with fingernail polish.

“I hold them by their ‘tiptoes’ very carefully while I do this, so I don’t break their fragile legs,” she says.

As many as 300 spiders live in her lab. Her golden orb web spiders (Nephila pilipes) from Taiwan live in 5-foot-high cages. Their stiletto-like black legs span more than 3 inches, and the walls of their homes consist of wedding-veil material. The sheer fabric mimics webs and allows the spiders to use their feet and claws to move about easily.

She buys bolts of veil material from bridal stores. When clerks congratulate her on her upcoming nuptials, she gets a kick explaining the real purpose of her shopping mission. “I get a lot of weird looks,” she admits.

There are only 200 arachnologists in the U.S., 40% of whom are women, according to the American Arachnological Society. People are usually startled to learn Danielson-Francois does research on spiders, “but once they hear how awesome spiders are and that you don’t have to be afraid of them, that changes minds,” she says.

One bit of folklore is true — spider sex is dangerous, at least for long-jawed orb weaver grooms in her lab. “We know they’re interested in mating when the female is sitting there, hanging with her jaws, her chelicerae, open. The male approaches, and they just run at each other and grasp each other by their jaws. Sometimes she eats him, usually after they’ve mated. Sometimes she eats him before,” says Danielson-Francois. She has found that only rarely does the male do the dining.

In the wild, females of this species outnumber males and welcome many suitors. “We’ve discovered that a male can scoop out previous male sperm and put his in,” she says. “What’s happening is sperm competition inside the female, and that’s why a female isn’t picky — she just lets the sperm from different males fight it out inside her.”

Though her husband, Serge Danielson-Francois ’91, has little interest in spiders, he has moved with her to Arizona, Kansas, Texas, and now Michigan for the love of spiders. A scholar in his own right, he has published most recently in Humanities magazine and teaches an online course on “The Messiness of Human Nature” for Humanities North Dakota. During the day, he teaches history and government at Academy of the Sacred Heart in Bloomfield Hills, Mich.

Their Matchbox couple status prevails: “It’s true love,” Danielson-Francois says. “He came out with me to my field site in Louisiana — lagoons covered in mosquitoes and filled with alligators, spiders, and venomous snakes.”