Duluth native discovers possible method to save Darwin's finches
A hummingbird in a person’s hand was the ripple that started the wave that set a Duluth schoolgirl named Sarah Knutie on the path to becoming a biologist.
“As cheesy as it sounds, it was the first time I went to Hawk Ridge,” Knutie said. “I saw a hummingbird in the hand and thought, ‘How cool is that to see it up close.’ I fell in love.”
Fast-forward to now: Knutie’s study of Darwin’s finches in the Galapagos Islands earns scientific acclaim today as her potentially species-saving findings are released in an article in the journal Current Biology. It amounts to an exhilarating discovery, the sort some scientists spend a lifetime in search of. What makes it even richer is that Knutie doesn’t have her doctorate yet. That comes later this year.
“I tell people about this project and they kind of say, ‘Wow, you can actually make a contribution to science,’” the 31-year-old University of Utah biology student said. “A lot of scientists have experiments and studies, but a lot of times they’re not applied.
“The fact this study may help really critically endangered birds is amazing.”
There are 14 species of Darwin’s finches on the Galapagos Islands (which are on the equator in the southern Pacific Ocean, west of Ecuador). Two of the species are critically endangered — the mangrove finch, with fewer than 100 remaining on Isabela Island, its only home, and the medium tree finch, with 1,620 left on its home of Floreana Island. The reason for the finches’ demise: a parasitic fly maggot that robs nests of their baby birds. The flies may have invaded the islands via ships and boats from the Ecuadorian mainland. Because the birds have no history with the flies and, thus, no inherent immunity, Knutie aptly described them as “sitting ducks.”
“From the perspective of the birds,” she said. “These things are from Mars.”
The flies are responsible for the decline of all species of Darwin’s finches. Knutie worked alongside University of Utah biology professor Dale Clayton during the course of three separate visits to the islands totaling one year between 2010 and 2013. She never set out to find a solution to the problem. Her aim was to study the effects of the fly on different hosts. Her “Eureka!” moment came in 2010, when she was sitting on her Charles Darwin Research Station porch and noticed the birds were chewing off fibers of frayed knots from her laundry line and taking the fibers to their nests.
“I knew that a mild pesticide worked at killing the fly,” she said before reciting her postulate, “Why couldn’t I spray cotton balls, give them to the birds and let them kill the parasites themselves?”
Introducing a predator to kill the fly could have been dangerous to the ecology of the islands. It would have taken 10-15 years to test candidate predators. Instead, Knutie introduced cotton balls treated with permethrin – the same stuff in head-lice shampoo.
Experiments showed it worked.
“To be honest, I didn’t know that it would,” she said. “It was a crazy idea, but I stuck to my guns and I proved a lot of people wrong.”
Her professor, Clayton, is listed as the senior author of the study. Knutie is the study’s “first author.”
“If the birds insert a gram or more of treated cotton (set out in dispensers) — about a thimbleful,” he said, “it kills 100 percent of the fly larvae.”
Knutie grew up in Duluth with parents Sandy and Steve Knutie. Sarah and her sister, Erin, are close but polar opposites. Erin was into the arts and earned a degree in interior design.
“I was always the kid playing in the dirt,” Knutie said. “I had insect farms, which my mom hated. I loved birds, and I had some really inspiring teachers.”
In speaking to the News Tribune for this story, Knutie realized she attended three Duluth schools that no longer exist: Chester Park Elementary, Woodland Middle School and Duluth Central High School. She did well in science, taking Honors biology, and really well at mathematics. She even started her academic career at the University of Minnesota, studying information technology. She hated it, and an adviser told her she could make a career out of her most beloved interests: animals and the outdoors.
She immersed herself in the U of M’s Department of Ecology, Evolution, and Behavior, studying bird behavior and even working at the U’s Itasca Biological Station and Laboratories. There, she studied reproductive hormones in birds and how stress affected reproduction. After graduation, she took a year off and traveled to Australia, California and Alabama to work on conservation projects. Throughout it all, she realized she had an inquisitive mind that asked good questions.
So, buoyed with confidence, she went to grad school at the University of Tulsa, where she did some work with a swallow bug — akin to a bed bug for birds. She got really interested in parasites of birds and found a preeminent authority in Clayton, who drew her to Salt Lake City for her doctorate work.
Her family never wavered in its support.
“My entire family is close,” Knutie said. “I talked to my mom five times today. I’m 31 and still in school, but I don’t have anybody telling me, ‘You need to get a career; you need to have money and babies.’ It’s always been, ‘Get your degree and do what you want.’”
“To walk in the footsteps of Darwin is amazing,” said Knutie, who found that in developing his theory of evolution by natural selection Darwin “did some pretty crazy stuff himself.”
He rode tortoises. He tied a stone to a marine iguana and threw it out to sea to see if it would survive. According to the website Truth in Science, he even ignored the finches that only later became his namesake. In his epic work, “The Origin of Species,” there is no mention of a finch.
In fact, it’s entirely likely that Knutie spent more time studying finches than Darwin ever did.
Still, the ghost of Darwin adds wonder to the place.
“It is an absolutely gorgeous place, and a very special place with a lot of history,” Knutie said.
But in order to work among Darwin’s inspirational playground, Knutie and others at both the research station and Galapagos National Park have to stumble over lava rock, get pricked by cactus spines, rise at 4 a.m. to greet the animals they study and tolerate the 108-degree midday heat.
For most, that means a hearty pair of boots, shorts and a T-shirt. For Knutie, it was different. She found out on her first trip to the island that she was terribly allergic to a lovely plant, with leaves colored like molten lava, by the name of Croton.
“It gives me hives,” she said. “My skin gets so inflamed you can tap on it like it’s a hard table. It’s the one allergy I have.”
To combat the prolific plant, Knutie had to wear two pairs of pants simultaneously as well as two long-sleeve shirts.
“That’s dedication, I guess,” she said.
Having already made such an exquisite discovery so early in her career, Knutie was bound to have post-doctoral options. Even while she works on her dissertation to complete her studies in Utah, she will begin work at the University of South Florida in July. She’ll work on a disease that is driving the extinction of frogs and salamanders there and around the planet. It’s called Chytrid fungus, and it coats the skin of amphibians. Because amphibians breathe through their skin, the disease essentially suffocates the animals.
“The fact is, animals are being moved around the earth to places they’re not supposed to be,” Knutie said. “It’s destroying whole ecosystems.”
Knutie made no promises that she’s going to solve this new conundrum. Before she starts, she’s scheduled to come home to Duluth for a visit. She’ll visit Hawk Ridge. She still finds inspiration there, among the raptors and other birds.
“I am so lucky that I found something I truly love to do,” she said. “Someone once told me you truly know what you love to do if you’d do it in your garage for free. I believe that.
“I love understanding these questions more than anything else in the world.”