Movin’ and poopin’ are two things often on Diego Ellis Soto’s mind – the movin’ and poopin’ of animals, that is.

Diego, a PhD candidate at the YBGC Center, is a movement ecologist who’s interested not only in how and where animals are moving, but also what they’re carrying along with them and depositing as they move – from cranes migrating across hemispheres to giant tortoises ambling throughout the Galapagos, animals contribute massively to the transport of nutrients and other resources throughout ecosystems. The Galapagos is where Diego spent his early years as a scientist studying how giant tortoises facilitate tree growth across the island by planting seeds in their poop. “I think of giant tortoises as gardeners of the Galapagos,” he says.                                                                                                                                                                                    

A long overlooked and perhaps unsightly phenomenon, nutrient and resource transport via animal consumption and defecation has drastic impacts on ecosystems: tortoises transfer tree seeds, hippos transfer digested savannah grasses to rivers, bears and seagulls transfer their fishy leftovers to upland environments. In the scientific literature, this process is called animal-vectored subsidies or, more broadly, zoogeochemistry, and it was the topic of Diego’s recent award-winning co-authored paper.                                                                                                                                                                                    

The study of these animal vectored subsidies asks four questions: 1) Where, how, and why are animals moving? 2) What habitats do animals use and avoid? 3) What food resources are available to and consumed by animals? and 4) Where and how do animals deposit these nutrients? These foundational questions and more are outlined by Diego and co-authors in their methodological roadmap to better understanding and accounting for animal-vectored subsidies in ecosystem dynamics, which won him and co-author Kristy Ferraro the Sidnie Manton Award for early career ecologists.                                                                                                                                                                                    

“[Animal-vectored subsidies] are really hard to measure, and it requires lots of different expertise,” says Diego on why such work has been often overlooked in past research. “We need to have an understanding of the movement ecology of animals, their nutrition and physiology, the ecosystems and habitats they inhabit, and put it all together with theory and mathematical models.”                                                                                                                                                                                    

If green plants are the lungs of the Earth, then animals are the veins, criss-crossing habitats, landscapes, and even entire continents in their daily movements and annual migrations while transporting a crucial, life-giving substance: nutrients. In doing so, animals can contribute significantly to the stability and functioning of ecosystems, and devoting work to better untangling these processes can help us design nature-based solutions and better understand human-animal interactions. In the context of our rapidly changing world, it also raises the question: what happens when these veins stop pumping? When populations plummet or species go extinct or habitat ranges and migration routes shift? What consequences are there at the ecosystem level if we lose entire migrations, such as wildebeest, or thousands of tortoises walking up and down Galapagos active volcanoes? These uncertainties led Diego deeper into the questions of zoogeochemistry and, eventually, to his groundbreaking new paper, which will help ecologists more explicitly account for the role of animals in nutrient transport and predict future changes in response to a rapidly warming climate and increasing human activities.                                                                                                                                                                                    

From one award to the next, Diego will be devoting his future research to questions around human-wildlife interactions as a NASA Future Investigator. A highly prestigious award, the Future Investigators in NASA Earth and Space Science and Technology (FINESST) grant recognizes Diego as an emerging leader in ecology and remote sensing and will fund him through the end of his PhD as he explores how human activities – such as Covid-19 lockdowns – impact animal movements on an increasingly crowded planet with former BGC Center postdoc Ruth Oliver and current postdoc Scott Yanco.                                                                                                                                                                                      

From the very beginnings of his career as a scientist, Diego has been fascinated by animal movement ecology; but, he now finds himself at the crossroads of basic and applied sciences and is particularly interested in how his animal movement work relates to human society and environmental justice. “So I want to do both – continue studying how animals move using new technologies, but also how we can change the status quo of who gets to do science, where we do science, who collects science data, and for whom we create science. I see myself as a servant of society and increasingly want to do so for historically underrepresented issues.”                                                                                                                                                                                    

The most rewarding aspect of Diego’s career, he says, is working with children – from bringing kids along to fieldwork expeditions in Ecuador and Germany to writing a children’s book about Galapagos tortoises, Diego is always exploring new and interesting ways to make his work more accessible to all, but especially to children. One of his most recent and passionate exploits has been in the realm of music: specifically, using animal noises and movements to create songs. In his pilot animal music project, Diego pulled together a mixed bag of tools, including inexpensive audio recorders and motion tracking AI, to make music out of everything from singing birds visiting the Yale Farm to termites moving in a petri dish. Now, he envisions a school program that would see children using similar inexpensive equipment to record and document their local biodiversity and create music with. To Diego, these kinds of initiatives seek to reimagine how citizen science data is collected by centering it in environmental and social justice – and, by centering kids, their creative energy, and the animals that live right outside their door.                                                                                                                                                                                    

If you ask Diego what’s up next for him, you’ll probably hear firsthand about his upcoming animal movement research with his NASA FINESST grant, his new ideas for uniting biodiversity and music, and maybe even what he’s planning to plant next in his garden. And you might also get a passionate speech about the importance of giant tortoise poop.

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