Dr. Valerie McKenzie, Principal Investigator

I am an Associate Professor in the EBIO department at CU. My research interests combine the fields of parasitology, disease ecology, microbiology, and conservation biology. I work in a variety of places ranging from locally in Colorado to tropical rainforests. Many of my current projects involve fieldwork, labwork, meta-analyses, and applied conservation activities.

Timothy Korpita, PhD Student


I am generally interested in microbial ecology as it relates to amphibian conservation. Specifically, I am interested in how the chemical environment of amphibian skin determines which microbes can live there. I also have some applied projects working with Colorado’s endangered Boreal toad. Teaching is also a significant focus for me, and I currently serve as the Graduate Teacher Program lead for the EBIO department. Website:

Brendan Hobart, PhD Student

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I’m an ecologist broadly interested in how climate change, anthropogenic disturbance, and community shifts alter the occurrence and outcome of species interactions, and what this means for conservation and management. I’m particularly intrigued by the question of whether interspecific interactions (e.g., predation, parasitism) mediate the response of focal species and communities to novel stressors. As a member of the McKenzie Lab, I currently study amphibians, their parasites, and how interactions between these two groups vary among habitats, communities, and climates. Website:

DreamTeam2019Melissa Chen, Tim Korpita, Alex Alexiev & Val McKenzie at Browns Creek for purple rain project 2019.

McKenzie Lab Alumni

Dr. Alexandra Alexiev, Former PhD student at University of Colorado Boulder: Alex’s PhD dissertation explored the fungal and bacterial microbiome on amphibian skin, as well as how probiotics can be better optimized in amphibian hosts by considering cocktail mixes of bacteria. Alex is now a postdoc at Oregon State University in Tom Sharpton’ lab. Website:

Dr. Melissa Chen, Former PhD student at University of Colorado Boulder: Melissa’s PhD dissertation explored the structure and function of skin-associated bacteria on amphibians, and asked how and whether resident skin bacteria are able to deter establishment of invaders. She designed a custom biofilm microcosm system, which she used to test hypotheses about how bacterial are able to deter establishment of an amphibian fungal pathogen. She also use novel Bayesian-inspired statistical approaches to infer cause-and-effect between microbial community traits and fungal infection risk and intensity. Melissa is now a postdoc at the University of British Columbia in Cara Haney’s lab. Website:

Dr. Christine Avena, Former PhD student at University of Colorado Boulder: Christine is a biological scientist with Kaleido Biosciences in Boston. She is currently working on a program focusing on infant gut microbiome health. Outside of her work, she continues to pursue her love of conservation through volunteer work on bat acoustic monitoring projects and surveys. Website:

Tiffany Prest-Hoefs, Senior Research Associate: Tiffany is a Lead Scientist with the consulting firm Booz Allen Hamilton. She is currently contracted out to the government as a Scientific, Engineering, and Technology Advisor (SETA).

Holly Archer (M.S.), Professional Research Assistant: Holly Archer, MS. Former Lab Manager of the McKenzie Lab. After an exciting and wonderful tenure as a lab manager, Holly decided to share her love of science by pursuing one of her lifelong dreams to become a middle and high school teacher. She recently completed a 2-year alternative licensure program to get her certification and just started her 3rd year of teaching at an arts-focused charter high school in Colorado Springs where she teaches Biology, Anatomy and Physiology, and Geography. She loves the rigor and constant problem solving of teaching as well as the ability to share her past lab experiences with her students.

Dr. Jessica Metcalf, Assistant Professor at Colorado State University: Jessica uses ancient DNA clean lab methods to directly sample genes from the past to answer questions in ecology, evolution, and forensics. She also applies these clean lab methods to microbiome research to understand the human microbiome during life and after death. She has since started her own lab! Website:

Dr. Se Jin Song, Former Senior Research Associate: Se Jin studied the gut bacterial microbiome across various mammalian groups and the factors that contribute to differences between these groups.

Dr. Lisette Arellano, Former PhD student at University of Colorado Boulder: Lisette’s projects focused on land-use change and parasite ecology in amphibians and mammals. Science communication and outreach are her other major areas of work. Lisette now works for the Golden Gate National Parks Conservancy as the Community Science Program Manager for One Tam, an interagency land management partnership in Marin County, California. Website:

Jordan Kueneman, Former PhD student at University of Colorado Boulder: Jordan completed his PhD in the McKenzie lab in Fall 2015. His dissertation spanned various topics involving microbial pathogen defense against Bd. His research interests include disease ecology, amphibian conservation, skin microbiome, microbial ecology, probiotics research. Website:

Dr. Doug Woodhams, Assistant Professor at University of Massachusetts Boston: Doug was a postdoc in the lab for 2 years before launching his own lab! Website:

Anna Peterson (M.S.), former Master’s student and CU Boulder: Anna’s thesis explored the role of non-native bullfrogs as a reservoir for Bd using field studies and experiments with amphibians from the Colorado Front Range ecosystem. After finishing her master’s degree, she continued on to complete a PhD from the University of Tennessee, where her dissertation research focused on understanding how post-Hurricane Katrina landscape change has influenced urban rodent communities and zoonotic rodent-borne pathogens in the City of New Orleans, Louisiana. She is broadly interested in issues that lie at the intersection of anthropogenic change, public health, and conservation. Anna currently works as a contract ecologist with the US Fish and Wildlife Service and is aiding in the development of a new early detection and rapid response program for invasive species across the Alaska Region. Website:

Ash Weier, Undergraduate research assistant and lab technician at CU Boulder. Ash worked on several microbial culturing projects, field experiments, and methods development related to the boreal toad research.

Rachel Martindale, Undergraduate research assistant at CU Boulder. Rachel worked on several microbial culturing projects related to the boreal toad research.

Graham Goodman, Undergraduate research assistant at CU Boulder: Graham went on to complete his PhD at the U of Utah. Now he is leading his own lab! Website:

Cerrise Weiblen, Undergraduate Honors Thesis mentee: Cerrise’s thesis explored the genome of Janthinobacterium lividum, a bacteria that is a top candidate for many amphibian probiotic trials.

Abby Kimball, Undergraduate Honors Thesis mentee: Abby’s honors thesis explored microbial communities on Colorado’s boreal toads. She’s currently a research assistant at CU Anschutz.

Julia Moy, Undergraduate Honors Thesis mentee: Julia worked as a laboratory/field assistant conducting DNA extractions, qPCR, and coyote scat surveys. Her honors thesis explored bullfrog parasites to examine biogeographic patterns of parasite loss in the invasive range of bullfrogs globally.

Alexandra Fresch, Undergraduate Honors Thesis mentee: Ale used her double major in EBIO and Creative Writing to produce an honors thesis that explores the reasons we find parasites gross and disturbing. Her thesis was a novel integration of psychology, biology, and humor.

Paige Littman, Former Undergraduate Researcher: Paige completed her MS at Colorado State University with Dr. Janice Moore. She studied parasite ecology in turkeys.

Robert Adams, Undergraduate Honors Thesis mentee: Robert did his honors thesis on paleoparasitology and studied 1500 year-old parasite eggs discovered from human mummy coprolites.

Nicolas Goulet, Undergraduate Honors Thesis mentee: Nic’s honors thesis explored ecological factors associated with the spatial distribution of West Nile virus cases in Colorado.