Research Magazine

When he arrived at Auburn University in 1993, fresh from postdoctoral work in Ontario, Dr. Geoffrey Hill was “Auburn’s primary bird man,” as he puts it in one of his books. He notes that, among the faculty of Alabama’s major universities, he was the only ornithologist around at the time and took to fielding bird questions from across the state. By that point, though, his interest in birds had already been growing for some 20 years — “literally since I’ve been 11 years old,” he explained.  “I was always a kid fascinated by animals,” Hill added, and he would roam his Kentucky neighborhood with friends, collecting snakes, salamanders and insects. But when he began to learn the basics of bird identification, the bugs and reptiles were soon forgotten.

Hill, a professor in Auburn University’s Department of Biological Sciences, joined the faculty at a time when the College of Sciences and Mathematics was in its infancy, having been formed from departments housed elsewhere within the university. From the start, he felt he had made the right choice in picking Auburn as his academic home base, observing that “ornithology is a lot of fun” as teaching assignments go and the climate, people and rural nature of the surrounding region are a perfect fit for someone who loves the outdoors.

In a certain sense, Hill studies all birds, counting and documenting as he goes, but throughout his career, he has honed in on certain species — house finches, Eastern bluebirds, American goldfinches, canaries, grosbeaks, the tufted titmouse and Henslow’s sparrow, to name a few. In particular, he has spent a lot of time analyzing and explaining the significance of bird coloration and its role in such things as warning away predators, providing camouflage and signaling a bird’s fitness as a mate. In fact, Hill has written two books on coloration — one a scholarly, two-volume tome, the other a lay reader’s guide released under the National Geographic imprint.

Because he’s known for his expertise on bird coloration, among other things, Hill finds himself contacted on occasion by media outlets like CBS News, when someone spots a rare, yellow cardinal, as an Illinois resident did earlier this year, following a 2018 sighting of a similar bird in south Alabama. The birds have been spotted in a handful of U.S. states, Hill noted. Though he has never seen one himself, Hill explained that they are yellow due to a genetic mutation and are probably “a little rarer than one-in-a-million,” with 10 or 12 such birds per year (out of about 50 million cardinals) in the eastern U.S. and eastern Canada.

Ivorybill Encounters

Hill has a keen ear, as well as a keen eye, when it comes to observing birds, and this proved helpful in 2005 and 2006 during a year-long search of the swamps of the Choctawhatchee River in Florida. Aided by a team of graduate students, he was able to discover and document a small number of ivorybilled woodpeckers in the area, years after many believed the bird to be extinct. The group made recordings of the birds’ distinctive “kent” calls and their double knocks on the hardwood trees that provide shelter and a buffet of insects for the woodpeckers.

In the book that followed, Ivorybill Hunters: The Search for Proof in a Flooded Wilderness, Hill documents with an almost philosophical flair the great effort that went into trying to bring back photographic evidence of the elusive birds, as well as the limitations of the search. He noted the group’s inability to get a good photo of an ivorybill woodpecker prompted him to improve his own wildlife photography skills, the results of which can be seen in such subsequent books as his National Geographic Bird Coloration from 2010.

Mitonuclear Ecology and the MitoMobile, a Lab on Wheels

For the past few years, Hill’s research has expanded beyond the world of birds to include a broad focus on mitochondria, the organelles that produce chemical energy for our cells. “Really, anything I did earlier, I think, is eclipsed by what I’ve done in the last 10 years,” Hill said. “The mitonuclear stuff will be the only thing I’m remembered for, if I’m remembered for anything…  I just think it’s a little ahead of its time, but it’s going to reshape evolutionary biology.”

Hill explained that “mitochondrial dysfunction makes up a large portion of inherited diseases in humans,” including cognitive diseases such as Parkinson’s and Alzheimer’s. Studying mitochondrial function in animals can provide insight into a host of health issues faced by humans, but the only effective way to do this testing is with fresh specimens. This fact severely constrained the research efforts of Hill and his colleagues for quite some time. They were limited to doing this type of work in their Auburn lab space or in a borrowed lab, if one happened to be near the location of an environmental event where such testing was needed. For example, Hill noted, after the 2010 Deepwater Horizon oil spill off the gulf coast of Alabama, it would have been useful for the group to test mitochondrial function in birds impacted by the spill, but there was no feasible way to make it work at the time.

After considering the dilemma at length, Hill and his fellow researchers came up with the idea of assembling a traveling laboratory, in the form of a customized recreational vehicle, and the MitoMobile was born. This sophisticated rolling lab is self-leveling, which helps stabilize equipment such as centrifuges, and it can go, essentially, anywhere there are roads, freeing Hill and colleagues to conduct mitochondrial research wherever the need arises.

Key collaborators on recent MitoMobile projects have been Dr. Wendy Hood, also of the Department of Biological Sciences, and Drs. Andreas Kavasiz and Bruce Gladden from Auburn’s School of Kinesiology.  The vehicle has already traveled to California and New York for research work, including a trip in June to study hybrid ducks.

“It’s really hard to get ahold of avian hybrids,” Hill noted, explaining that “birds don’t hybridize very often in the wild” and that raising them in captivity is difficult. However, after years of wanting to study the mitochondrial function of mixed-species birds, Hill stumbled upon the information that two ducks — the mallard and the Muscovy — are hybridized for the restaurant industry, and he and his team would be able to test several of these at the location where they are raised.

The opportunity allowed Hill and his colleagues to explore some of their ideas about mitonuclear speciation, the general concept that the mitochondrial genes in an organism interact with its nuclear genes in ways that are integral to the organism’s ability to thrive and to the formation of species themselves. Hill hopes to continue to move these ideas forward and is excited to see that “a lot of young scientists are really interested in this and are coming to me, asking questions and picking up projects.” He added that “once people start to revolve a career around these ideas, then it’ll start to really take hold… I think it’s going to really change the field, but it’s going to take awhile.”

By this point in his career, Hill is known around campus as a veteran scientist and a renowned expert in his field. As Dr. Ed Thomas, interim dean of the College of Sciences and Mathematics, explained, “Professor Hill has been a leading researcher in COSAM for over two decades. From his work on genetic origins of coloring in birds, to studying bioenergetics in animals and humans all across the country using the MitoMobile, to his work as a curator in the Auburn University Museum of Natural History, Geoff has not only advanced our fundamental understanding of biological systems, he has also been an excellent ambassador for Auburn biological sciences research.”

“I’ve been very happy at Auburn,” Hill noted. “I was just thinking the other day… I think a lot of people have some regrets, like ‘Aw, if I’d only gotten that job at Harvard…’ I really don’t think that. I don’t know where I would’ve been happier.”