What Goes Down Must Come Back Up, and Other Frogging Adventures

With all of our belongings on our backs we hiked 3 km down to the San Gerardo Biological Station. The hike was spent enjoying views of the Arenal Volcano and the rainforest while trying not to slip. The San Gerardo Station is situated in the middle of the Children’s Eternal Rainforest, the largest private reserve in Costa Rica. It is named the Children’s Eternal Rainforest because students from many countries raised the necessary funds to create the preserve and protect this unique tropical forest. We spent one week in the rainforest learning about forest dynamics, tropical forest deforestation and destruction, and amphibians. Our evenings were spent on night hikes looking for frogs, which I learned is called “frogging”.

Costa Rica is home to over 190 species of frogs and toads, many of which are endemic meaning they are only found in Costa Rica. In the 1980s, amphibians worldwide experienced “overnight crashes” where entire species suddenly disappeared. In the past 20 years 168 amphibian species have vanished across the globe. In the early 1980’s, 51 species of frogs were regularly observed in the Monteverde region. Then in 1987, only 25 of the 51 expected frog species were observed. The cause of this crash is highly debated. Some attribute it to climate change while others believe that it was caused by chytrid fungus. Climate change is associated with warming temperatures and as our planet warms, plant and animal species climb to higher elevations. The changing environment likely reduced the suitable habitat for amphibian species in this region. Chytrid fungus is an aquatic fungus that attaches to frog skin and feeds on the frog’s keratin. The fungus can kill a frog in just 16 days. The fungus is very hardy and can survive in the environment for long periods of time. This fungus has been found in Monteverde. Likely, both the changing environment and chytrid fungus both contributed to the loss of such a vast number of an amphibian species in this region.

Frog species have been on the decline in Costa Rica for several years, but recently a significant number of frog species have reappeared. In fact, 12 out of the 25 species that had disappeared in Monteverde in 1987 have recently reappeared. This resurgence is fascinating and gives me hope for the future.

Just like the number of frog species going down and then back up, we too had to go back up out of the Children’s Eternal Rainforest. Traveling uphill in the bright sunshine made the trail out of the rainforest seem much longer than the trail into it. (My pack seemed much heavier, too.) Leaving was also hard as I was sad to leave knowing it will likely be a long time before I am able to return. Hopefully though, when I do, perhaps even more frog species will have reappeared.

Andriana Miljanic

Emory University