Glaucia Del-Rio joins the Florida Museum of Natural History as curator of ornithology

Press release from Florida Museum of Natural History

GAINESVILLE, Fla. – Last week, Glaucia Del-Rio officially stepped into her role as curator of ornithology at the Florida Museum of Natural History. She replaces retired curator David Steadman, who held the position between 1995 and 2021.

Del-Rio was raised in São Paulo, Brazil, a sprawling urban complex with high-rises and suburbs, as well as a substantial periphery of low-income housing where she spent most of her childhood. There were few natural areas near her home, and the only birds that ventured into the neighborhood were those most tolerant of urban development, such as rock pigeons and house sparrows. Yet as far back as she can remember, Del-Rio felt an affinity for nature and science — particularly biology — that she tried to nurture whenever possible.

“I grew up close to a public library, where my aunt worked. I would go there constantly and just look through encyclopedias,” she said.

When she entered college, her interest in biology blossomed into full-on fascination. She began an internship at the local natural history museum, where she was initially tasked with cleaning bird specimens. “My father would playfully chide me for working so hard only to get a cleaning job, but while cleaning specimens, I could read their tags and learn their names. I think my adviser saw my excitement. After a few weeks of working there, he invited me on an expedition to collect birds in the Amazon. I was hooked.”

Her fastidiousness in the collection paid off in other ways as well. She began noticing subtle differences among woodpeckers that didn’t quite match what she read in the literature. Birds that were considered one species had variation in their overall sizes and the patterns of their plumage that seemed to line up with the type of environment they were collected in.

Her adviser at the museum helped guide her observations and encouraged her to try sorting out the problem herself by collecting data. The experience would form the basis of much of her later work.

After graduating, she felt certain that she wanted to pursue a career in science and enrolled in a master’s program at the University of São Paulo. She wanted to conduct research that would help conserve Brazil’s rare and endangered birds and found the perfect project waiting for her practically in her own backyard. In 2004, a biologist working on the outskirts of São Paulo near Del-Rio’s home discovered a new species of antwren that was restricted to the once-widespread marshes bordering the city.

“When it was described, people began looking for it all over the São Paulo state and couldn’t find it anywhere else,” she said. “We knew it was endangered, so I basically said, ‘I’m going to do this as a master’s project. I’m going to go after that bird!’”

This was easier to envision than carry out. The reason it had taken so long for anyone to discover the bird was due in part to its elusiveness. Del-Rio’s neighborhood also had a high crime rate, which made the field work risky, and the marshes are notoriously inhospitable. “It’s not like you can kayak through rivers and reach the marshes or get to them by boat. Basically, you put on waders and walk kilometers into the swamp.”

She became familiar with the birds after persistent treks into the marsh. But the more time she spent with them, the less she enjoyed the work. Her research made it clear that unless someone intervened, the species that had only just been given the courtesy of a name would be extinct within a few decades.

Just next door, the Amazon rainforest cloaked an endless procession of tropical birds that had received similarly little scientific attention, compared with their neighbors in the Northern Hemisphere. She made forays into the Amazon during her time as a student, collecting birds and observing patterns on a grander scale than the ones she’d found hidden in the museum cabinets.

“I fell in love with the Amazon. From the beginning, it became my favorite place to work. In Brazil, it’s the area about which we know the least, in terms of diversity.”

The Amazon is home to the world’s second-largest river, where even the tributaries are so wide they can act as a significant barrier to animal dispersal. A single bird species often looks slightly different on either side of a river. A species might have silky black throats on one side and gray throats on the other; if one listens closely enough, the song and calls also differ within some species.

It’s unclear why Amazonian birds use rivers to divvy up their territory. Many of them live in the forest understory and have eyes adapted to the dim shadows and sunflecks that illuminate their environment. Attempting to cross a river in full sunlight could potentially blind them, or at least make for an uncomfortable experience. 

Del-Rio chose two closely related species — the white-breasted antbird and harlequin antbird — that demonstrated this pattern to focus on for her doctoral research at Louisiana State University Museum of Natural Science. The two antbird populations retained their differences along the length of a river, with the exception of the narrow headwaters, where they mingled and hybridized.

“Hybrid zones are laboratories for understanding how species stay different species,” she said. “Usually, the answer is they have different ecological requirements, but in the Amazon, it’s not just the ecology. The environment is very similar on both banks of the river.” With no obvious explanation for their behavior, Del-Rio began looking for clues in DNA. That work, which is ongoing, has shown that diversification has been enhanced by rivers across the Amazonian Basin, leading to the formation of similar-looking but genetically distinct species that have yet to be discovered. Many have small ranges that leave them particularly vulnerable to extinction.

The two birds she studied for her dissertation get their name from their habit of following trains of army ants along the forest floor and stealing food from the soldiers. They carry out their raids under cover of darkness, and Del-Rio and colleagues suspect they do so by means of a hyper-developed sense of smell, but no one’s yet tested the idea. They’re also nomadic, following the moving buffet carried by ants as it winds through the forest, stopping for only a few days at a time when the queen needs to lay eggs.

No one knows how the birds care for their own eggs while being constantly on the move. To find out, someone will need to track them. “This is one of the things I really want to do with my students. We need to put tags and GPS trackers on the birds to find out where they’re going and how much they’re moving.”

Just before joining the Florida Museum, Del-Rio worked as a postdoctoral associate at the Cornell Lab of Ornithology. She also completed a postdoctoral position at the Harvard Medical School Boston Children’s Hospital, where she learned genomic techniques she could use to study tropical birds in an entirely new way. Along with her other duties as curator at the Florida Museum, she wants to establish a collection of cell cultures, both as a scientific resource and as insurance against extinction.

“It’d be the first cell culture bank in any museum, and it’s something we could have longterm, even for birds that are threatened or endangered. If we fine tune some of the methods, these cells could be used to ‘clone’ birds in the future if necessary.”