Why Nancy Chen Is Mapping the Family Tree of Florida Scrub-Jays

Understanding the bird's genetic diversity could yield insights about how best to protect it and other threatened species.

When Nancy Chen heads into the Florida scrub, she carries a pocketful of peanuts, which leave little grease stains on her pants. They’re not a snack—for her or the Florida Scrub-Jays she is hoping to attract. (It’s in fact illegal to feed the jays without a permit from the U.S. Fish and Wildlife Service.) The sleek blue birds are too clever to fly into mist nets, so Chen uses them to lure the jays for research that may one day point to a strategy for preserving the species.

Calling on the jays in person is a rare treat for Chen, an evolutionary biologist at the University of California, Davis and, starting in July, assistant professor at the University of Rochester. She studies how the birds’ genomes—an organism’s complete set of genetic material—are changing as the population shrinks due to habitat loss. “The fieldwork is the most fun, but really the driving force in my work is being able to increase our understanding of what’s going on out there in nature,” Chen says.

For the population of scrub jays Chen visits in central Florida, there are decades of blood samples and records of each bird’s birth and relatives. Chen is drawn to the rare opportunity this trove gives her; there are very few cases where scientists have tracked genetic diversity in a single group of animals over many years. Doing so for the scrub-jays, which are classified as threatened, may help not only bolster their population, but also reveal lessons for conserving other vulnerable species.

It’s not a project Chen would have expected to find herself dedicating years of work to. Although she spent her childhood visiting the Los Angeles Zoo, camping with her parents, and dreaming of studying wild animals, Chen entered Harvard University planning to go into medicine—until an ornithology textbook at the campus bookstore caught her eye. Then, as a graduate student at Cornell University in 2008, she investigated a mysterious drop in the scrub-jay population her mentor was tracking around Archbold Biological Station in Venus, Florida. Chen and her colleagues never did find enough evidence to know for sure what had happened, but she became enchanted by the scrub-jays’ intelligence and habit of helping to raise their younger siblings.

When Chen made the switch from studying medicine to birds, her interest in genetics followed her. So she created a family tree for the Archbold population of scrub-jays going back to 1969 and has been tracking how closely related the jays are to each other. Her work has led to a worrying discovery: Although the Archbold population is among the largest in the state, scrub-jay strongholds around it are dwindling. As a result, fewer immigrants are flying in to mate with the locals. Chen found that her group of scrub-jays has become more inbred since 1990, and fewer chicks are hatching or surviving their first year. This means it won’t be enough to conserve the largest populations of scrub-jays; the smaller groups around them are vital for maintaining a healthy gene pool.

Chen is now working on predicting how many copies of a given bird’s genes might show up in future generations. This will help her figure out exactly how immigrant birds contribute to the population’s genetic diversity, an important insight for assessing the effectiveness of different conservation efforts—for both the Florida Scrub-Jay and other bird species in decline.

In her spare time, Chen is also dedicated to increasing diversity in the sciences. She is on the American Ornithological Society’s Diversity and Inclusion Committee and is co-running a workshop focused on identity and unconscious biases. Many people don’t have the chance to spend enough time around birds to develop a passion for ornithology, Chen says. So attracting people from different backgrounds can strengthen both research and conservation efforts.

As immigrants from Taiwan, her parents worked hard to secure her education, Chen says. But they also encouraged her to pursue traditional paths like medicine, law, or engineering. It was an ornithology professor in college who showed her that a career in evolutionary biology was a viable option, she says. Now she is committed to making sure students from all backgrounds have similar opportunities. “It just seemed like a natural thing to do,” Chen says.