Dr. Seth D. Newsome

Professor of Biology and Associate Director UNM Center for Stable Isotopes
My research has three overarching foci. First, I quantify niche breadth at multiple levels of biological organization –– individuals to communities –– to better understand the energetic basis of community assembly and structure. Second, I use controlled feeding experiments in which I vary the chemical composition and concentrations of dietary macromolecules to understand how animals process protein, lipids, and carbohydrates. This enables me to trace energy flow within organisms at the molecular level, which provides insights into which exogenous and endogenous resources are used to maintain homeostasis. Third, I often adopt a deep temporal perspective that compares species interactions in modern and ancient ecosystems to provide unique data on the full range of animal behavioral and ecological flexibility; such information is important for designing effective long-term management and conservation strategies.

[email protected]

Lab Members


Dr. Christy Mancuso

My research interests are focused broadly around nutrition and travel history reconstruction in both animal and human systems. My Ph.D. research at the University of Utah focused on using stable isotope biomarkers in keratin tissues to recreate diet and travel histories to examine questions related to forensic sciences, adolescent diets, and the impact of public policies on school lunch programs. For my postdoc, I am interested in expanding my these research interests in these areas as an NIH ASERT-IRACDA Fellow through the use of carbon, nitrogen, and hydrogen isotope analysis of individual amino acids. Specifically, my postdoc work will focus on examining the role of the gut microbiome in amino acid synthesis and refining assessment of geographic region of origin and animal movement in keratinous tissues.

[email protected]

Dr. Geraldine Busquets Vass

I am interested in understanding the foraging ecology and reproductive physiology of marine megafauna via analysis of intrinsic biomarkers in animal tissues. During my Ph.D. at CICIMAR-IPN (La Paz, Mexico), I studied the foraging ecology, movement patterns, and physiology of blue whales using stable isotope analysis in metabolically active (skin) and inert (baleen) tissues. My postdoctoral research is sponsored by CONACYT and will characterize the foraging ecophysiology and migratory patterns of blue, gray, fin, and humpback whales in the eastern Pacific Ocean using bulk tissue and amino acid isotope analysis of baleen plates. This study will enable us to assess the vulnerability of baleen whales to environmental change that we anticipate will inform species-specific management plans.

[email protected]

Dr. Nico Lubcker

My research combines multidisciplinary approaches to study various aspects of organismal ecophysiology. During my Ph.D. at the University of Pretoria in South Africa, I developed intrinsic biomarkers of dietary niche use and nutritional status of individual southern elephant seals. Using stable isotopes and steroid concentrations in keratinous tissues, I advanced the use of minimally invasive approaches to assess the physiological mechanisms that individuals use to cope with prolonged periods of fasting, and to assess the amino acid transfer between mothers and their fetuses during gestation. For my postdoc, I aim to extend my horizons into desert ecosystems and develop new biomarkers to quantify water balance and metabolism, as well as continuing to develop new proxies to assess nutritional stress and capital versus income breeding.

[email protected]

Alexi C. Besser

Ph.D. Candidate
I am very broadly interested in the connectivity between freshwater aquatic and terrestrial ecosystems. My current research focuses on using amino acid isotope analysis to study energy flow from terrestrial floodplain habitats to river food webs. The Middle Rio Grande in central New Mexico is a critical place to study this linkage because it is intensively regulated by dams to control flooding and extract water for municipal and agricultural use, which has decreased the extent and duration of overbank flooding. This has effectively eliminated the link between the terrestrial floodplain and river that is likely essential to aquatic ecosystem function. Characterizing the role of terrestrially-derived energy in the food webs of heavily-regulated rivers will inform management decisions regarding controlled overbank flooding at habitat restoration sites in these systems.

[email protected]

Conner Mertz

Ph.D. Student
I am fascinated by the complexity and elegance of how cells maintain homeostasis, respond to stress and defend themselves against infectious agents. I am particularly interested in the interactions between microbes and their hosts. Since all animals host microbes in their gut, I plan to look at the gut microbiome’s impact on host physiology and protein metabolism. My graduate research will integrate two active fields: next-generation genetic analysis and compound-specific stable isotope analysis. This will allow us to describe the community composition of the gut microbiome while also exploring the role microbes play in the synthesis of amino acids used by the host. Host-microbe interactions range from mutualistic to pathogenic, therefore understanding these interactions are integral to our understanding of health and disease.

[email protected]

Jessica Johnson

M.Sc. Student
I am interested in small mammal community ecology. My research involves understanding the impact of climate change on the small mammal community at the Sevilleta National Wildlife Refuge. As the LTER monthly mammal trapping manager, I spend most of my year trapping for small mammals and hope to use the stable isotope data and quantitative magnetic resonance data I collect to help guide our understanding of life history traits of these individual communities. By applying a genus-level analysis to small mammals occurring at the Sevilleta, I will be looking for patterns of diversity and abundance with the use of climate sensitivity functions. By using this multivariate analysis, I hope to better define which specific life history traits of each genera can best explain patterns in individual community response to drought and climate change.

[email protected]

Dr. Philip J. Manlick (Postdoc): Research Biologist, U.S. Forest Service (Juneau, AK)

Dr. Oliver Shipley (Postdoc): Senior Research Scientist, Beneath the Waves (Herndon, VA)

Dr. John P. Whiteman (Postdoc): Assistant Professor, Old Dominion University (Norfolk, VA)

Dr. Christy J. Mancuso (Postdoc): Thermo Scientific (Albany, NY)

Dr. Emma A. Elliott Smith (Ph.D.): Postdoctoral Associate, Smithsonian Institution (Washington, DC)

Dr. Alexi C. Besser (Ph.D.): Postdoctoral Associate, Arizona State University (Tempe, AZ)

Deborah Boro (M.Sc.): Natural Heritage New Mexico (Albuquerque, NM)

Laura Pages Barcelo (M.Sc.): Bosque Ecosystem Monitoring Program (Albuquerque, NM)

Christina Blevins (M.Sc.): Sandia National Laboratory (Albuquerque, NM)

Jessica Johnson (M.Sc.): Los Alamos National Laboratory (Los Alamos, NM)

Dr. Rodrigo Bastos: Postdoctoral Fellow, Universidade Federal de Pernambuco (Recife, Brazil)

Juliano Coletto: Ph.D. Student, Universidade Federal do Rio Grande (Rio Grande, Brazil)

Andre Costa Pereira: Ph.D. Student, Universidade de Brasilia (Brasilia, Brazil)

Dr. Marilyn L. Fogel: Distinguished Professor and EDGE Director, UC Riverside (Riverside)

Michael Fox: Ph.D. Candidate, Scripps Institute of Oceanography (La Jolla)

Sean Hixon: Ph.D. Student, Pennsylvania State University (College Station)

Dr. Rocio Loizaga de Castro: Research Professor, Centro Nacional Patagonico (Puerto Madryn, Argentina)

Dr. Paul L. Koch: Distinguished Professor and Dean, UC Santa Cruz (Santa Cruz)

Sabina Llamazares: Ph.D. Student, Universidad de Buenos Aires (Buenos Aires, Argentina)

Nico Lubcker: Ph.D. Candidate, University of Pretoria (Pretoria, South Africa)

Dr. Karin Maldonado: Research Professor, University of Chile (Santiago, Chile)

Natasha Phillips: Ph.D. Candidate, Queens University (Belfast, Northern Ireland)

Dr. Francisca Santana: Postdoc, Universidad de Antofagasta (Antofagasta, Chile)

Juliann Schamel: Biologist, Channel Islands National Park (Ventura)

Clarissa Teixeira: Ph.D. Student, Universidade Federal de Santa Catarina (Santa Catarina, Brazil)

Matthew Tietbohl: Ph.D. Candidate, King Abdullah University of Science and Technology (Thuwal, Saudi Arabia)

Dr. Damian G. Vales: Research Professor, Centro Nacional Patagonico (Puerto Madryn, Argentina)

Katie Wedemeyer-Strombel: Ph.D. Candidate, University of Texas El Paso (El Paso)

Hannah Wellman: Ph.D. Candidate, University of Oregon (Eugene)

Dana Wright: Ph.D. Candidate, Duke University (Beaufort)

Dr. Nico deBruyn: Professor, Pretoria University (Pretoria)

Dr. Stanley Gehrt: Professor, Ohio State University (Columbus)

Dr. Marilyn L. Fogel: Professor and EDGE Director, UC Riverside (Riverside)

Dr. Chris Harrod: Professor, University of Antofagasta (Antofagasta, Chile)

Dr. Keith A. Hobson: Professor, Western Ontario University (London, Canada)

Dr. Tyler Kartzinel: Assistant Professor, Brown University (Providence)

Dr. Douglas Kelt: Professor, University of California Davis (Davis)

Dr. Kate Lyons: Assistant Professor, University of Nebraska (Lincoln)

Dr. Karin Maldonado: Professor, Universidade Adolfo Ibañez (Santiago, Chile)

Dr. Craig McClain: Executive Director, Louisiana Marine Consortium (Chauvin)

Dr. Gabriela Nardoto: Professor, Universidade de Brasilia (Brasilia, Brazil)

Dr. Luciana Riccialdelli: Professor, Centro Austral de Investigaciones Cientificas (Ushuaia, Argentina)

Dr. Andy Read: Professor, Duke University Marine Laboratory (Beaufort)

Dr. Pablo Sabat: Professor, Universidade de Chile (Santiago, Chile)

Dr. Irene Salinas: Associate Professor, University of New Mexico (Albuquerque)

Dr. Zachary Sharp: Distinguished Professor, University of New Mexico (Albuquerque)

Dr. Felisa Smith: Professor, University of New Mexico (Albuquerque)

Dr. Cristina Takacs-Vesbach: Professor, University of New Mexico (Albuquerque)

Dr. Justin Yeakel: Assistant Professor, University of California Merced (Merced)