EMIGRA is an international team of natural and social scientists working to understand the telecoupled social and environmental systems of North American migratory species, to improve their management, and discover new approaches to the problems of complex interconnected systems.

laura lopez-hoffman
Laura López-Hoffman

University of Arizona

Laura López-Hoffman is a Professor in the School of Natural Resources and the Environment, and a research professor at the Udall Center for Studies in Public Policy at the University of Arizona. She is also an affiliated faculty member of the UA James E. Rogers College of Law. The objective of her research is to contribute to the development of environmental policies and institutions that protect ecosystems and sustain human well-being.


Aaron Lien

University of Arizona

Aaron Lien is an Assistant Professor of Rangeland Ecology and Adaptive Management in the School of Natural Resources and the Environment at the University of Arizona. His work is focused on solving emerging environmental governance challenges in coupled natural human systems. Aaron is an environmental social scientist with broad training in theories of human behavior and decision making, and frameworks for analyzing governance institutions.

Jonathan Derbridge

University of Arizona

Jonathan Derbridge is a Research Scientist in the School of Natural Resources and the Environment at the University of Arizona, and research director for the López-Hoffman Lab. He is a wildlife ecologist who works on a range of applied conservation questions related to endangered populations, introduced species, migrations, and ecosystem services. He also specializes in science communication through art and video-editing.


Charles C. Chester

Brandeis University

Charles C. Chester teaches global environmental politics at Brandeis University and at the Fletcher School of Tufts University, and serves as the Board Chair of Bat Conservation International and as Chair of the Yellowstone to Yukon Conservation Council. He is currently building the website,, an online guide to global environmental politics. He co-edited the volume Conservation & Climate Change: Landscape and Seascape Science, Planning and Action (Island Press 2012) and authored Conservation Across Borders: Biodiversity in an Interdependent World (Island Press 2006). 

Columba González-Duarte

The New School for Social Research

Columba González-Duarte is Assistant Professor of Anthropology at The New School for Social Research in New York City. Through her research, Columba examines the conservation dynamics of the monarch butterfly across three nations, analyzing the connections between NAFTA's agri-food industry, labor migration, and the decline of the monarch population. She also collaborates with scientific and Indigenous communities in Canada, the United States, and Mexico to document their knowledge and ways of relating to migratory insects. Dr. González-Duarte's academic practice is shaped by feminist ethics of care, promoting a different form of justice that values the well-being of both humans and more-than-humans during their migratory journeys across North America.


José R. Soto

University of Arizona

José R. Soto is an Assistant Professor in the School of Natural Resources and the Environment at the University of Arizona. He is also an affiliated faculty at UA’s Graduate Interdisciplinary Programs in American Indian Studies and Arid Lands Resources Sciences, along with UA’s Department of Agricultural and Resource Economics (courtesy appointment). His research centers on the modeling of coupled natural-human systems at different spatial and temporal scales—for both fundamental insight and practical real-world applications.

Juanita Sundberg

University of British Columbia

Juanita Sundberg is an Assistant Professor in the University of British Columbia Geography Department. She brings the insights of feminist political ecology and the sensibilities of an ethnographer to bear on nature conservation, border security, and militarization. One of Juanita's current projects examines the environmental dimensions of United States’ border security policies in the United States-Mexico borderlands, with a specific focus on protected areas like national wildlife refuges.

Rodrigo Medellín

National Autonomous University of Mexico

Rodrigo Medellín is an ecologist at the Instituto de Ecología at the National Autonomous University of Mexico. He is known for his work in the field of bat conservation, jaguars, bighorn sheep, and ocelot. He works has worked for the American Museum of Natural History, and he has been an ambassador for the International Union for Conservation of Nature. Rodrigo was President of the Society for Conservation Biology (2013-2015) and Co-Chair of the CITES Animals Committee (2002-2012).​

Gary McCracken

Gary McCracken

University of Tennessee

Gary McCracken is a Professor of Ecology & Evolutionary Biology at the University of Tennessee in Knoxville. His research concerns the distribution of animals in space, their behavior and interactions, and resulting impacts on genetic population structure. Currently, these organisms are bats, insects, and fungal and viral pathogens. The projects in his lab involve field studies combined with molecular assays, and ongoing collaboration with The Institute for Ecological Modeling at UTK to better inform data collection and to provide predictive analysis and interpretation.

Jay Diffendorfer

US Geological Survey

Jay Diffendorfer Is an applied ecologist working at the Geosciences and Environmental Change Science Center. Trained as an ecologist, he originally worked on spatial ecology and conservation biology, modelling reptile and amphibian responses to restoration scenarios in the Everglades. Jay then worked as an assistant and full professor at San Diego State University, studying relationships between urbanization, fire, and invasive species on a native flora and fauna in southern California. Since arriving at USGS in 2008, he currently works on science related to the energy-environment nexus, ecosystem services, and applied ecology. 

Darius Semmens

US Geological Survey

Darius Semmens joined the USGS Rocky Mountain Geographic Science Center in 2008 as a Research Physical Scientist. His current research interests include the development of new methods and tools for the assessment and valuation of ecosystem goods and services - the specific benefits that we derive from nature. More specifically, his work involves developing methods and tools that can account for the spatial and temporal dynamics of service production and incorporate that into more rigorous analyses of the tradeoffs associated with landscape management.

Wayne Thogmartin

US Geological Survey

Wayne Thogmartin is a quantitative ecologist with the U.S. Geological Survey conducting scholarly research in population ecology for animals declining in abundance, translating science into guidance for practical, applicable management decisions. He is particularly interested in the novel application of analytical methods to complex settings in wildlife ecology, population biology of rare species, and habitat relationships of birds, bats, and butterflies. He holds a BA from the University of California, San Diego, an MS from the University of Arkansas, and a PhD from Southern Illinois University, Carbondale.

Ken Bagstad

US Geological Survey

Ken Bagstad is a Research Economist working with the USGS’ Geosciences & Environmental Change Science Center in Denver. He uses GIS and modeling to quantify, map, and value ecosystem service flows across the United States and internationally. Ken is co-leading work to construct natural capital accounts in the United States at national and regional scales. He is also interested in improving scientific data and model interoperability and reusability through artificial intelligence and the semantic web.

James Dubovsky

Jim Dubovsky
Wildlife Biologist (retired)

Jim Dubovsky is a Wildlife Biologist who spent 29 years with the Migratory Bird Program of the U.S. Fish and Wildlife Service. During his career he had extensive experience developing migratory bird monitoring programs, regulations and policies with federal, state, and provincial biologists and administrators in the U.S., Canada, and Mexico to improve the management of birds and their habitats. He also worked with numerous universities and nongovernmental organizations to advance the science underpinning management of birds.

James DeVries

Ducks Unlimited, Canada

James DeVries is a Research Scientist at the Institute for Wetland & Waterfowl Research for Ducks Unlimited, Canada. He is responsible for co-ordinating applied research within Western Canada and his research provides key feedback to enhance conservation program delivery. Jim conducts extensive field work and analyzes large databases that relate local and landscape level habitat conditions to waterfowl productivity and responses in biodiversity metrics.

Brady Mattsson

Brady Mattsson

University of Natural Resources & Life Sciences, Vienna

Brady Mattsson is a Senior Scientist with the Institute of Wildlife Biology and Game Management at the University of Natural Resources and Life Sciences, Vienna.  He develops and tests modeling approaches to answer questions in ecology and to inform sustainable management of wide-ranging birds and mammals.  His projects span regional to continental scales, including the integration across scales. These are collaborative efforts that integrate fields of population and community ecology, economics, mathematics, and decision science. Focal systems include northern pintails in North America and large mammals in the Alps.


Michelle Haefele

Colorado State University

Michelle Haefele is a Research Scientist at Colorado State University. Her current research projects include estimation of the total economic value of the National Park Service, the cost of wildfire suppression and fuel reduction treatments, economic impacts of hunting, and the non-market costs and benefits of oil and gas development. Past research includes studies of the economies of wilderness and national monument gateway communities; the economic impacts of public lands on rural communities, and analysis of the changing economy of the West.


Ta-Ken Huang
Tamkang University, Taiwan

Ta-Ken Huang is an Assistant Professor in the Department of Water Resources and Environmental Engineering. He is interested in coupled natural-human systems, environmental economics, and spatial analysis. His dissertation research evaluated how wind energy expansion impacts the ecosystem services provided by bats.

The Student Research Team

EMIGRA Student researchers

The EMIGRA Project’s initial data gathering phase is powered by a diverse team of student researchers from the University of Arizona, Brandeis University, and Mount Saint Vincent University. Our students are even more multi-disciplinary than the senior team, coming from majors in ecology, environmental studies and related fields, as well as dance, computer sciences and international global studies. Many of the students are avid outdoor enthusiasts and enjoy everything from spelunking and terrarium building to rollerblading and archery.