Resilience in a Scenario of Environmental Injustice: The Paradox of the Golden-Eyed Coffee Frog (Agalychnis annae)

William Duellman described this frog in honor of his then-wife Ann S. Duellman (1). Medium to large in size, it is unmistakable: emerald green dorsum, intense blue flanks and thighs, and golden eyes that give it its most autochthonous name. The term "blue-sided frog" imposed by English speakers does not mean much to us; "Golden-eyed Coffee Frog" better evokes its essence and history.

Historically, the species inhabited the mountains of Costa Rica—from the Cordillera de Tilarán to the Cordillera de Talamanca—between 600 and 1,650 meters above sea level (2). Its distribution coincided with coffee-growing areas, especially in the Central Plateau, where it was part of the everyday landscape.

I grew up in the late 1980s in San Francisco de Heredia, once the main coffee city of the Valle Central. From the mid-20th century to the 1970s—my father told me—it was common to find this frog while picking coffee. Those people, many students working during their vacations, were startled by the cold animal with a characteristic smell in their hands or baskets. It was part of the most traditional image of the Valle Central. Today it is an urban nucleus where coffee is barely a memory. Coffee plantations gave way to residential developments, condominiums, free trade zones, and shopping centers. And with them, the Coffee Frog—like so many other native species—disappeared from the everyday landscape. Over a decade ago, I documented this loss (3), warning about the accelerated transformation of the landscape. The children of this area, for more than 30 years, have grown up without the Coffea arabica plants or its Coffee Frog.

I did not have the good fortune, like my professors, to interact with this species in the 1980s and 1990s, when they witnessed the decline of more than a dozen iconic species (4). For me, arriving after that crisis has meant studying the Coffee Frog in a different context: not its disappearance, but its enigmatic return.

As I advanced in my graduate studies, I began to see the species return. It did not appear in the best-preserved forests where for more than a decade I had hoped to find it (5, 6), but in unexpected places: house gardens, artificial ponds, surviving coffee farms, riparian forests in the middle of the urban core. At the beginning of the 2000s, populations began to recover. From 2004 to 2019, it went from Endangered (EN) to Vulnerable (VU) according to the Red List. Little by little, the Coffee Frog reappeared in peri-urban areas, and with it, questions such as: what is the status of the species in the country? Where is it and why? An emerging priority in amphibian conservation is to understand how species respond to humanized landscapes (7). Thanks to the Proyecto Rana de Cafetal, citizen science, and a network of public-private collaborators, we have clearer hypotheses, where A. annae is an example of that agenda in action.

Citizen science and collections in action

The Proyecto Rana de Cafetal, a citizen science initiative, was fundamental in documenting this recovery. Through iNaturalist and Facebook, with the collaboration of hundreds of people, we compiled more than 350 records since the year 2021, complementing historical museum records.

Species distribution models (8) revealed that the frog could be in wider areas than previously thought. After five years, the preliminary data we are consolidating in a manuscript (Acosta-Chaves et al., in prep.) are revealing: before 2000, one-third of the records (33.2%) were in protected wilderness areas; today that figure is barely 4.9%. In contrast, biological corridors concentrate 58.8% of recent records.

Contrary to what was believed, the current distribution is the result of multiple independent reappearances. Many populations in the center of the country have an affinity for open and disturbed habitats, as predicted by Hoffmann (9) and Arguedas et al. (10). The difference is that now, thanks to citizen science, we detect that affinity in sites where conventional methods would not have found them.

Inhabitant of an archipelago of urban refuges

During the last five years, we have traveled through multiple sectors in Heredia, Alajuela, and Paraíso de Cartago in search of the species. It has not been an individual achievement, but a community effort.

In Concepción de San Rafael (Heredia), the naturalist Jorge Corrales has monitored the species for years, in his garden and in abandoned coffee tanks belonging to neighbors. He proposed that the local government declare it a natural heritage of the canton, together with the Critically Endangered Holdridge's Toad (Incilius holdridgei). Hopefully, other municipalities will wish to copy this initiative, and why not, the country finally celebrate the leaf frogs as a national symbol.

At the Recinto de Paraíso of the Universidad de Costa Rica (Cartago), where I was a professor for a decade in the Ecotourism program, we began systematic counts with students. Initially, it was not on our species list, but from 2017 it began to appear abundantly in the campus's natural lagoon. A few kilometers away, at the Lankester Botanical Garden, the frog appeared in lagoons surrounded by gardens and ornamental plants. Both populations became living laboratories for that student community, serving as motivation for future professionals and managers of ecotourism and conservation.

At Finca Doka Estate (Poás), we worked with local guides and workers to raise awareness about good practices, especially given the high influx of tourism. At La Catalina Botanical Garden, Freeth Hernández—gardener, guide, and conservationist—built artificial ponds with his own hands. Currently, his ponds protect eggs, tadpoles, and adults. These spaces create a local network of people trained to monitor and protect the frog. Together with Freeth, we have surveyed private properties in Birrí de Heredia, documenting the species in fragments of riparian forest and abandoned coffee plantations. To these sites are added other local actors who maintain ponds and rivers on their properties, true refuges for the species. However, many of these places face the uncertainty of land-use change. Their high commercial value, despite being so modified and far from what traditionally interests conservation, makes it unviable to think of acquiring them for formal protection.

We have also visited multiple sites where the frog was expected but did not occur or was not detected. In Monteverde, in Atenas, and San Ramón, I carried out exhaustive surveys without finding a single individual. Those absences also speak and have helped us understand some of the biogeographic and climatic reasons that explain the current distribution, factors we are analyzing in the manuscript we are preparing.

Other colleagues work in Monteverde, Cerros de Escazú, Santa Ana, Zona de los Santos, and Coto Brus. I cannot tell all their stories here, but I hope they will do so in future issues of AmphiBios. The conservation of the Coffee Frog belongs to no one; it is a collective effort where each record, each absence, and each collaborator adds a piece to the puzzle.

At each site, the frog shares habitat with at least 16 other anuran species, including glass frogs (Hyalinobatrachium fleischmanni, Espadarana prosoblepon), the Marsh Frog (Isthmohyla pseudopuma), and Peralta's Frog (Lithobates taylori), as well as the endemic bird Melozone cabanisi (Cabanis's Ground Sparrow). Protecting A. annae means protecting an entire community that depends on these anthropized landscapes.

The conservation paradox: does only preserving the forest matter?

Despite its apparent recovery, the frog faces threats beyond the chytrid fungus or climate change. The greatest is a legal framework that does not protect the ecosystems where it really lives. Costa Rica's Forest Law No. 7575 defines "forest" restrictively, excluding tree-covered coffee plantations, grasslands, and early successional vegetation. These forgotten ecosystems, which A. annae uses for reproduction, do not require major permits to be modified by powerful developers. This is not only a technical problem, but one of environmental justice.

Peri-urban communities in the GAM—where the bulk of endemic species are concentrated—are disproportionately affected by the loss of ecosystem services. When a tree-covered coffee plantation is eliminated, not only trees and breeding sites disappear; the capacity to regulate water, climate, and populations of insect vectors decreases. Runoff floods become more frequent, infiltration into aquifers is interrupted, and our food supply is threatened. Heat waves, droughts, and mosquito-borne diseases such as dengue, zika, and chikungunya are increasingly common at intermediate elevations, where they were not previously recorded with this intensity.

Since that warning a decade ago (3), the pace of urbanization has accelerated. Condominiums and real estate projects appear almost spontaneously, devouring the last fragments of habitat, even in declared biological corridors. Administrative bureaucracy is an obstacle as lethal as climate change. Legal modifications are urgently needed with political actors and decision-makers.

Allies on the path: Café Britt and Save The Frogs

Conservation cannot depend only on obsolete laws. Fortunately, there are allies in companies and NGOs.

Café Britt launched a special "Mérito" edition dedicated to the Coffee Frog, donating one thousand dollars in research equipment—including high-quality sound recorders—that open new questions about its acoustic behavior, reproductive phenology, and response to urban soundscapes.

Save The Frogs supports a pilot volunteer plan. This year, the zookeeper Gage Denney (Naples Zoo, Florida) collaborated in the construction of artificial ponds, habitat cleaning, and monitoring at La Catalina Botanical Garden and at Finca Ecoorgánica Sarapiquí. Involving people with specialized skills is fundamental to thinking about in situ conservation projects and, why not, ex situ.

The ethics of conservation in a context of environmental injustice

The precautionary principle (in dubio pro natura), enshrined in Costa Rica's Biodiversity Law No. 7788, is often ignored. Unfortunately, this is the case for our protagonists, the Coffee Frog and the Cabanis's Ground Sparrow. Rapid Biological Assessments in urban or agricultural areas are limited to species lists, without considering endemism, sensitivity to disturbance, or ecosystem services. The impunity of tree cutting during holiday weekends is an everyday occurrence. The lack of technical criteria should not justify the loss of critical habitats outside protected areas (7). Science exists, but it is of little use without institutional and political will.

A symbol for Costa Rica

The Red-eyed Tree Frog (Agalychnis callidryas) has been the unofficial symbol of Costa Rican biodiversity. But the Coffee Frog, although morphologically similar, tells us a different story: that of a resilient species that has learned to survive on the margins of environmental damage. Declaring it a national symbol would be recognizing that humanized landscapes also deserve protection.

But visibility must be accompanied by responsibility. It is not about turning the frog into a tourist attraction without consideration for its welfare. We have already documented cases of excessive approach, manipulation, and capture as pets. Nor is it about translocating it without technical criteria. Although it exists in Panama (11), most of its population is concentrated in the Central Plateau, with recent records in Zona de Los Santos and San Vito de Coto Brus (8, 12). Moving it to other regions without criteria based on genetic and ecological analyses would not only be irresponsible but could put both the translocated populations and the recipient communities at risk. This is a line of research that urgently needs to be started more seriously. For now, our research will provide a baseline to make these decisions in a more informed manner.

What comes next?

The work continues. One of my future research lines will focus on urban and peri-urban landscapes, because the fate of this species—and of so many others that share its habitat—is played out in the interstices of our civilization.

But science alone is not enough. We need political action. It is urgent to reform the laws to recognize the ecological value of these forgotten ecosystems. We need local governments to protect urban biological corridors, demanding rigorous environmental impact studies and effective compensation. And we need the Coffee Frog to be recognized for what it is: a symbol of the resilience of life in the Anthropocene.

The conservation of this frog is not the whim of biologists and conservationists. It is an investment in the resilience of our communities. The loss of amphibians—natural mosquito predators—has been associated with an increase in vector-borne diseases in Latin America (13). In the GAM, the disappearance of its habitats not only impoverishes our biodiversity; it exposes us to health and environmental problems that were not previously common at our elevations. One Health reminds us that human, animal, and environmental health are inseparable.

The story of the Coffee Frog teaches us that conservation is not only about pristine ecosystems, but about everyday decisions in our own neighborhoods. If we can learn this lesson, perhaps we will still be on time to protect the entire community of life that depends on the landscapes we share.

Acknowledgments

This story is born from the collective effort of many people and institutions. I thank the professors and colleagues who have guided this path—Héctor Zumbado, Gerardo Chaves, Federico Bolaños, Viviana Arguedas, Gilbert Alvarado, and Adrián García—for their wisdom and pioneering work. To those who participated directly: Paula Acosta, Carolina Balma, Freeth Hernández, Kerry Krieger, Gage Denney, Randall Obsney, Jorge Corrales and Vincenzo Rizzo. To those who reported valuable observations: Gustavo Murillo, Naomi Méndez, Henry Sandí, Henry Fallas, Alejandra Rodríguez, Adrián Delgado, Luis Vega, Mark Wainright, Francisco Vargas, and all the citizens on iNaturalist and Facebook.

We thank the CIBET of the Universidad de Costa Rica for institutional support through research project C5262. To Café Britt for its generous donation of equipment and its "Mérito" edition that makes the species visible. To Save The Frogs for its volunteer work in the field. And to SINAC and CONAGEBIO for permit ACC-PI-RE-07-2021, which made citizen science possible.

References

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