Finding and catching endangered frogs in the cloudy mountains of Panama

A giant hand holding a plastic bag appears in the sky. With the fist almost closed, it lunges at the ground, trying to catch something, and fails. Once again, the hand jumps from side to side, trying to catch the frog, which is faster. It fails. There is more leaping, more plastic, more speeding, and finally, inside the close fist, the frog is caught. The giant hand ties the bag and places it inside a backpack.

El Valle de Antón, in Panama, is not only a picturesque town located in the crater of an extinct volcano in the Panamanian highlands, but is it also, from my journalistic perspective, a perfect place for biological research, with its cooler temperatures, its mountains, waterfalls, its biodiversity, and the cloud forests.

Researchers from the University of Nevada, Reno, seem to think so, too, as a team of women scientists consisting of two postdocs, one college student, two high school students, and two journalists embarked last August on a trip from Reno to El Valle, a 2-hours’ drive from Panama City.

The reason for the trip is one of horror and hope: there is a highly lethal disease called chytridiomycosis that has been devastating for Panamanian amphibian populations, including the iconic Panamanian golden frogs (Atelopus varius/zeteki), their beloved national animal. This and other species were rumored to be extinct. However, the University and other research teams found evidence that several amphibian species are persisting, and even recovering, long after the lethal disease outbreaks in the 1990s.

Now the University team, led by associate professor Jamie Voyles in the Department of Biology, travels twice a year, during wet and dry transition periods, to Panama to collect samples from the frog skin secretions as the Chytridiomycosis is a fungal disease that affects their skin and all its functions. Then, in the laboratory, they conduct experiments to test for changes in the pathogen – called Batrachochytrium dendrobatidis or Bd – in the frogs. They found that the frogs now have better defenses against the pathogen than before. They are fighting back! 

Walking in the wet boots of a scientist

The day starts early, at 7 in the morning. It takes a ride up the mountains, on steep slopes, in a 4x4 truck with geckos stuck to the windshield to arrive at each site, some of which are fairly remote. Dressed with rain boots and rain jackets, the scientists carried all their research equipment in waterproof backpacks. 

But getting to the site of each transect was the easy part. It then took a memorized hike in the forest dodging barbed wire and fallen trees and walking in zig zags from one side of the river to the other, sometimes losing sight of the other crew members due to the fog, to finally arrive at the transects. I stopped several times to empty the water that kept filling my borrowed rain boots.

At each site, the researchers take a moment to collect biological data, such as water and air temperature, humidity, and water pH, before they try catching the frogs, explained Carolina Lambertini, postdoctoral associate at the biology department at the University.

Then, the search begins. They have three focal frog species: the Panamanian common rocket frog (Colostethus panamansis), Warszewitsch’s frog (Lithobates warszewitschii) and the Panamanian golden frog (Atelopus varius/zeteki). But they also catch and sample other species if they find them, to detect the pathogen.

Walking up the stream, they were able to find and catch the two first species and a salamander, but we could not find any golden frog. Researchers haven’t found any golden frogs in these transects since 2012-2013. Some frogs were harder to catch than others. The rocket frog is faster and harder to catch and ended up leaping from the hands to the t-shirts of the researchers.

Before catching the frog, and when possible, they take the frog’s body temperature and the surface temperature.

“We then try to catch them using plastic bags, to avoid contamination, and once in the bag we get their body temperature, the time of the catch, and at what part of the transect they were collected; we also write if they were in a rock, moss, or so on,” explained Maria Delia Basanta, the other postdoctoral associate who traveled with us. 

At the end of each transect, the researchers sit in a circle on the river bank and start the sampling process in the field. While inside the bag, frogs are weighed and measured with the Snout-Ventral Length, or SVL, which is the measurement taken from the tip of the frog's snout to the cloaca–the opening for the digestive and reproductive tracts.

One of the students works on collecting data.

“With gloves, we take the frog from the bag, and with a swab, we follow a sterilized protocol that consists of swabbing the legs five times, the feet five times, hands five times, and 10 on the belly,” added Basanta. During the swabbing process, some of the frogs stay quiet, some play dead, and others like to stretch, showing off their long legs.

They take notes of all the characteristics and, once all the frogs have been sampled, they are released back into the transect while the team walks back down the stream.

“The idea with the swabbing is to detect this pathogen. Then, at the lab, we study how the frogs are affected, and try to understand how the amphibian communities are prevailing,” Basanta continued.

After releasing the frogs, the crew finds a different location to have lunch, chat about what they found, and prepare for the rest of the day, which sometimes consisted of doing some sample processing at home, and some other times included projects with the community. Postdoctoral associate Basanta dressed several times as a bright yellow golden frog to teach kids and teenagers at the local schools about the importance of these amphibians and the protection of the ecosystems.

Ongoing research

Some of the lab work is done at The Smithsonian Conservation Biology Institute's Center for Species Survival and El Valle Amphibian Conservation Center in Panama. It is also done by students and researchers at the University.

Lambertini is researching what is the role of their skin secretion as an immune response against the infection, and Basanta is trying to see if genetic changes are happening in the amphibians in comparison with the samples taken before the pathogen arrived.

Voyles, who didn’t travel this time to El Valle, explained that what they have found is that frogs now seem to have better defenses against the same pathogen.

“We have learned that it's not the pathogen that has changed in this system, but rather that the amphibian seemed to be fighting back with their defenses, their immune systems,” she explained.

They are trying to understand how this process is happening for different species because they all have slightly different immune responses to the infection.

“Some species are doing well. The species called Lithobates warszewitschii is recovering much better than many of the other species in the area, particularly compared to the golden frog, which is still present but it's very hard to find. So we want to understand the difference between these two species. Why has one recovered so well and the other one is still struggling to recover from this disease outbreak?”

The grant that Voyles's team currently has will keep going for two more years, but they are hoping to find more opportunities to keep doing research.

“It is really important to understand why these species have gone missing, and how we can facilitate their recoveries. From another perspective, as we know from the recent COVID pandemic, there's a lot that scientists don't understand about infectious diseases, so this research is also useful,” Voyles added.

Back to El Valle de Antón, with the India Dormida mountain, a profile that resembles a sleeping indigenous woman, as the background, groups of people celebrated last August 14, the Golden Frog Day with a week of activities that included collecting trash from the streets, science fairs with students, and a lot of dancing.

You can watch a YouTube video of the reserach: Golden Mission: Conserving Panama’s Last Golden Frogs.

About the author

Vanesa de la Cruz Pavas is a science and environmental journalist from Colombia. She recently graduated from the M.A. in Media Innovation program at the Reynolds School of Journalism. She now works as a Science Communication Specialist for the Hitchcock Project for Visualizing Science at the University of Nevada, Reno.