Gerardo Avalos, Ph.D.


Center Director


Costa Rica


B.S. in Biology
University of Costa Rica

M.S. in Tropical Ecology and Conservation
University of Missouri-St. Louis (MO, USA)

Ph.D. in Tropical Ecology and Conservation (Ecophysiology)
University of Missouri-St. Louis (MO, USA)


SFS 4910/4920 Directed Research
(The School for Field Studies)

SFS 2050 Language, Culture and Society of Costa Rica
(The School for Field Studies)

Multivariate Statistics, Natural History of Costa Rica, Ecology of Palms
Associate Professor (University of Costa Rica)

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Faculty Profile

Gerardo Avalos holds a Ph.D. and an M.S. in plant physiological ecology and conservation from the University of Missouri at St. Louis. After obtaining his B.Sc. in Biology at the University of Costa Rica, Gerardo began his graduate studies at the University of Colorado at Boulder, and then he transferred to the University of Missouri – St. Louis, where he investigated the physiological ecology of lianas using a construction crane to reach the canopy working as a fellow from the Smithsonian Tropical Research Institute in Panama. His dissertation examined the light acclimation of tropical lianas to temporal and spatial changes in light availability at the surface the forest canopy. His current research interests include the biomechanics of tropical palms, the carbon sequestration and functional trait ecology of palms, invasive plant ecology, and the functional ecology of hummingbirds including network dynamics across three trophic levels. After serving for 6 years as the Center for Sustainable Development Studies resident ecologist, Gerardo became the Center Director in 2007. He is a Full Professor at the University of Costa Rica where he teaches Botany, Ecology, Natural History, and Multivariate Statistics.

Academics & Research

Areas of Expertise

  • Carbon sequestration
  • Functional ecology of hummingbirds
  • Multivariate statistics
  • Palm allometry
  • Physiological ecology of tropical plants
  • Plant biomechanics
  • Tropical ecology and conservation

Professional Affiliations

  • Member, Association for Tropical Biology and Conservation (ATBC)
  • Member, Society for Economic Botany
  • Member, Botanical Societry of America
  • Member, Editorial Board of Oecologia (Ecophysiology section)
  • Coordinator Scientific Committee of the Ornithological Association of Costa Rica
  • Editor of Zeledonia, the journal of the Ornithological Association of Costa Rica
  • International Palm Society (IPS)
  • Red Latinoamericana de Ecofisiólogos Vegetales (REDLEV)

Research Interests

I am interested in the physiological adaptations of tropical plants to spatial and temporal changes in the availability of light, especially the characters that are responsible for the expression of plasticity at the extremes of the light gradient in a tropical forest: the understory and the canopy. My research have covered different groups, including birds, insects, and plants, and currently include the biomechanics of tropical palms, functional trait ecology, carbon sequestration, and the ecological morphology of hummingbirds especially sexual size dimorphism.

Research Projects

This project examines the symbiotic relationships between plants, hummingbirds, and mites in a tropical cloud forest. By capturing hummingbirds, collecting pollen and mites from hummingbird plumage, and using action cameras to record flower visitation, we are mapping the web of interaction across three trophic levels (pollinators, plants, and nectar-eating mites). Mites use hummingbirds to colonize flowers and disperse in a relationship called phoresis. The project seeks to unravel the trophic complexity of this assemblage in one of the most diverse environments in the Neotropics, such as the tropical cloud forest. This project is carried out in collaboration with the Center for Research in Microscopic Structures (CIEMIC) of the University of Costa Rica.

I have been working on palm ecology for a long time. I explored the population growth and illegal extraction dynamics of Euterpe precatoria, the allometric relationships of over 7 species of tropical palms, and more recently the generate allometric equations based on key morphological characters to understand how the capacity for carbon sequestration varies among palm species from different strata. I have applied these equations to estimate the amount of carbon that palms contribute to tropical forests with the aim of improving our estimations of carbon sequestration in tropical habitats. More recently, I am exploring the functional ecology of critical traits such as specific leaf weight to estimate the carbon sequestration of an entire individual palm.

I fell in love with hummingbirds since my undergraduate years. I have explored the dynamics of pollination in the highlands and mid-elevations of Costa Rica looking at how the morphology of hummingbirds affect their plan use and how this usage differs among species and sex within a species. More recently, I have examined the evolution of sexual-size dimorphism in hummingbirds. Our current project is looking at tri-trophic level interactions in a pollination network in cloud forests.

This is a project that I am developing in collaboration with the Hiroshima Green Legacy Foundation, the Hiroshima Botanical Garden, the Lankester Botanical Gardens in Costa Rica, the University of Costa Rica, and SFS, to establish the descendant of trees that survived the atomic bombing of Hiroshima in public places in Costa Rica to serve as symbols of peace. Under the current conditions of global warming, war, corruption, greed, and inequality, it is urgent to create a message of resilience to show that humanity, like the trees that survived Hiroshima, can rise again, and create a culture of social justice and peace. Right now, I have several seedlings of the ancient tree Ginkgo biloba and I have used them to give talks on the need to build a culture of peace. Read here

Grants and Awards

Keynote speaker to the International Palm Society meeting in San Jose, Costa Rica, May 2008.

Research Gate

Visit Dr. Avalos’ Research Gate profile to view select publications.


Select Publications

Salguero-Hernández, G. & G. Avalos. (2019). Report of bird captures in the páramo of Cerro Buena Vista, Costa Rica. Zeledonia 23(1): 55-59.
Chacón-Madrigal, E., Avalos, G., Hofhansl, F., Coronado, I., Ferrufino, L., MacVean, A. & D. Rodríguez. (2019). Biological invasions by plants in continental Central America. Chapter 9 in: Global Plant Invasions, Springer Verlag.
Avalos, G., Emilio, T., Andersen, K. M., & Alvarez-Clare, S. 2022. Frontiers in Forests and Global Change, 5:1021784. doi: 10.3389/ffgc.2022.1021784.
Avalos, G., Cambronero, M. & Vergnani, C. 2022. Frontiers in Forests and Global Change 5: doi: 10.3389/ffgc.2022.867912
Avalos, G. 2019. Still searching the rich coast: Chapter 4 in Pullaiah, T. (editor). Global Biodiversity Volume 4: Americas. CRC Press, Florida, USA.
Chacón-Madrigal E., Avalos G., Hofhansl F., Coronado I., Ferrufino-Acosta L., MacVean A., and Rodriguez D. 2021. D.R., Joshi, S., Upadhyaya, M.K. and Shrestha, A. Global Plant Invasions, London: Springer Nature.
Avalos, G., E. Chacón-Madrigal, & L.G. Artavia. 2021. Chapter 5 in: Volume 5. American and Caribbean Invasions. John Wiley & Sons.
Avalos, G., Gei, M., Ríos, L.D., Otárola, M.F., Cambronero, M., Alvarez-Vergnani, C., Sylvester, O. and Rojas, G., 2019. Oecologia 190(4):757-767.
Avalos, G., O. Sylvester, M. Cambronero-Quesada, & A. García-Segura. 2022. In: Pulido-Silva, M.T. & N.L. Sander. Usos de Palmas en Latinoamérica.


Avalos, G., Emilio, T., Alvarez-Clare, S., & Andersen, K. M. (Eds.). (2022).


Kandlikar, G., Carita-Vaz, M., Kriebel, R. Vargas, G., Michelangeli, F. Cordero, R., Almeda, F., Avalos, G., Fetcher, N., & Kraft N. J. B. 2015. 100TH Annual Meeting of the Ecological Society of America, Baltimore, Maryland.
Hager, A. & G. Avalos. 2015. Conference: 21st Annual Conference, International Society of Tropical Foresters - Conserving biodiversity across multiple use landscapes through strategic governance and land-use planning, Yale School of Forestry and Environmental Studies, New Haven, Connecticut.
Avalos, G., G. Lee & A. Soto. 2013. Proceedings of the Association for Tropical Biology and Conservation, San José, Costa Rica, June 2013.
Avalos, G. and G. Lee. 2012. III Congress of Ornithology, Costa Rica. San José.
Sylvester, O. and G. Avalos. 2009. Meeting of the Latinamerican Network of Botany, San Jose, Costa Rica, November 2009.
San Ramon, Costa Rica, July 2008.
May 2008. The conference versed on the Functional Ecology of Palms in Costa Rica.
In the annual reunion of the Association for Tropical Ecology and Conservation in Michoacán, Mexico, July 2007.
M.G. Gei and G. Avalos. 2006. IX latinamerican Interntional Symposium of Botany, Santo Domingo, Domenic Republic, May 2006.
Avalos, G. & M. Mauricio Fernandez. 2005. Congress of Conservation and Wildlife Management, 21 to 25 February 2005, Universidad Nacional, Heredia, Costa Rica.
Avalos, G. & E. Bermúdez. 2005. Congress of Conservation and Wildlife Management, 21 to 25 February 2005, Universidad Nacional, Heredia, Costa Rica.
Avalos, G. 2003. IV Congreso Nacional de Biología Clodomiro Picado, San José Costa Rica.
Avalos, G., A. Soto, J. Veenstra, T. Smith and C. Keller. 2002. Proceedings of the Association for Tropical Biology, Panama city, Panama, June 2002.
Avalos, G. 1998. VII Congreso Latinoamericano de Botanica: Diversity and Conservation of plant resources in Latin America. Mexico DF, Mexico, in October 1998.
Avalos, G. & S.S. Mulkey. 1997. Tropical Diversity: Origins, maintenance and conservation. Symposium and Annual Meeting. Association for Tropical Biology and OTS, Costa Rica San Jose June 1997.