Sofia Rodriguez Brenes

Academic Director at the Organization for Tropical Studies
herpetologist | ethologist | teacher | amateur potter | mom

I am a biologist interested in amphibian ecology, animal behavior, natural history, communication, and infectious diseases. I also enjoy teaching, in the field or classroom, at high school or university level, and in English or Spanish.

I studied biology at the University of Costa Rica graduating with a focus on Herpetology (the study of frogs, salamanders, lizards, and snakes). I earned a doctorate in ecology, evolution and behavior at The University of Texas at Austin. At UT Austin, I studied the spread of a devastating fungal pathogen (better known as chytrid or Bd) through frog populations in Costa Rica and Panamá. I also investigated how infections with this pathogen affect the frog’s behaviors and reproductive success.

My teaching experience as an instructor or teaching assistant includes high school classes on Sea Turtle Conservation, Island Ecology, and Whales with Ecology Project International (Costa Rica and Mexico) and Biological Treasures of Costa Rica (Duke University Talent Identification Program), as well as university classes on Herpetology and Vertebrate Zoology at UCR and Animal Behavior, Animal Communication, and Biostatistics at UT Austin.

My continuing research interests are at the intersection of animal behavior, sexual selection, and disease ecology, especially changes in behavior caused by infection. I am passionate about teaching, especially in the field and hope to immerse many young and curious minds to the wonders of our biosphere.


Tracking the spread of chytrid

University of Texas at Austin

While at UT Austin for my PhD, I studied the spread of a devastating fungal pathogen (better known as chytrid or Bd) through populations of the túngara frog in Costa Rica and Panamá. For this project I organized and led two expeditions in the Darién Gap—a remote wilderness of primary forest separating Central (Panamá) and South America (Colombia). At the time, this was the only region in the Americas where the wave of chytrid spread had not been documented. Aside from sampling for the pathogens and assessing the frog communities, these two expeditions allowed us to connect with the indigenous Emberá community.

To learn more about this multi-year study, have a look at our paper and check out the acompanying video and feature article.

Rainy seasons 2010 - 2014

Behavioral and reproductive effects of chytrid infection

University of Texas at Austin

Chytridiomycosis is a devastating disease caused by a chytrid fungi, and one of the main causes of amphibian population declines and extinctions across the world. This disease does not affect all species the same way—for some its effects are lethal, while others seem to be tolerant. There is growing evidence that chytridiomycosis might have sub-lethal effects in tolerant or resistant species with potentially long term population-level consequences. For a part of my doctoral dissertation I tested the hypothesis that pathogen-induced stress might incur a trade-off in investment between the immune response and reproduction. I studied how the chytrid influences the reproductive behavior and reproductive output of the túngara frog. Specifically, using recordings of male mating calls in the wild, field experiments and laboratory phonotaxis trials, I assessed if the infection with chytrid influences the mating calls of túngara frog males, their attractiveness to females, and whether the infection in adults affects the number of tadpoles. A couple of papers based on this work are forthcoming.

Rainy seasons 2013 - 2015

Selection on major histocompatability complex genes in chytrid-infected frogs

University of Texas at Austin

In collaboration with Tiffany Kosch, Arnaud Bataille and Bruce Waldman, we assessed the potential that pathogen–driven selection can favour major histocompatibility complex (MHC) alleles that confer immunological resistance to specific diseases. We compared the allelic diversity of major histocompatibility complex II (MHC) genes between more vulnerable, declining highland populations and tolerant lowland populations of túngara frog. We found that frogs from highland regions had MHC variants that confer resistance to the chytrid, and given that overall genetic variation persisted, the prevalence of MHC variants was most likely due to directional selection. In chytrid–infected populations in lowland sites, however, individuals with only one of the chytrid resistance MHC alleles were more frequent, suggesting that this combination of alleles might confer a selective advantage. Overall, our work suggested that selection on MHC loci in the túngara frog varies with the favourability of the habitat for spread of the chytrid. Read more about this work in the paper.

Dry seasons 2010 - 2013


Organization of Tropical Studies, USA/Costa Rica

  • Tropical Biology: An Ecological Approach
    • 2018 Course co-coordinator

The University of Texas at Austin, Texas, USA

  • Animal Behavior
    • 2012, 2013, 2016 Teaching assistant
  • Animal Communication
    • 2012 Teaching assistant
  • Biostatistics
    • 2010, 2011 Teaching assistant

Duke University Talent Identification Program, USA/Costa Rica

  • Tropical Treasures of Costa Rica for High School students
    • 2011 Assistant instructor
    • 2012-2015 Lead instructor
    • 2016 Lead instructor (missed, pregnancy + zika)

Ecology Project International, Costa Rica/Mexico

  • Marine Biology and Island Ecology Program; and Whales Program. Baja California Sur, México
    • 2010 Instructor
  • Leatherback Sea Turtle Ecology Program. Costa Rica
    • 2008, 2009 Instructor

University of Costa Rica, Limón, Costa Rica

  • Ecotourism I & II
    • 2007 Lecturer

University of Costa Rica, San José

    Teaching assistant:
    • 2000, 2001 General Biology
    • 2002, 2003 Introduction to Biology
    • 2004 Ecology
    • 2005 Herpetology
    • 2006 Amphibians
    • 2006-2008 Vertebrate Zoology
    • 2008 Field Biology


PhD, Ecology, Evolution and Behavior

The University of Texas at Austin
2010 - 2016

Ecologia y Conservacion Tropical

Organization for Tropical Studies, USA/Costa Rica.

BSc, Biology

Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica

1998 - 2005

Scholarships and Grants

  • 2015
  • Faculty for the Future Fellow, Schlumberger Foundation ($50,000)
  • Graduate Dean’s Prestigious Fellowship Supplement, The University of Texas at Austin ($1,000)
  • 2014
  • Doctoral Dissertation Improvement Grant (DDIG), National Science Foundation, USA ($12,000)
  • Doctoral Dissertation Improvement Grant (DDIG), Ecology, Evolution and Behavior Program, UT Austin ($8,000)
  • Faculty for the Future Fellow, Schlumberger Foundation ($50,000)
  • Graduate Dean’s Prestigious Fellowship Supplement, The University of Texas at Austin ($1,000)
  • 2013
  • Faculty for the Future Fellow, Schlumberger Foundation ($50,000)
  • Graduate Dean’s Prestigious Fellowship Supplement, The University of Texas at Austin ($1,000)
  • 2007
  • Scholarship for the Course Tropical Ecology and Conservation. Organization for Tropical Studies ($4,500)
  • 2007
  • Animal Behavior Society Student Travel Grant. ($600)


When I am not teaching, performing experiments in the field or lab, or lately, parenting, I love to sit down behind a pottery wheel.