Searching for the last Podocarpus harlequin frogs

by Berglind Karlsdóttir - July 2, 2018

I’m writing this blog as my 7 months of internship with Durrell’s Conservation Science and Saving Amphibians From Extinction teams are coming to an end. My time here has been incredibly rewarding, with a bunch of new experiences, perspectives, skills and interesting colleagues. However, the last three weeks I have been out of the office on a little expedition with my colleague Phil Jervis and partners at La Balsa de los Sapos, Andrés Merino and Freddy Almeida. The trip, funded by the Mohamed bin Zayed Species Conservation Fund, took us to southern Ecuador. Even though it was separate to my internship, it links in with my work here at Durrell. That’s why I want to share my experiences on this trip with you!

But first an introduction to the amphibian crisis and why this work is so important. Over 40% of the world’s amphibians are threatened with extinction – a rate higher than for any other class of vertebrates, so mammals, birds etc. These declines in populations are happening because of habitat destruction, climate change, pollution, the pet trade and the chytrid fungus. Chytrid originates from the Korean peninsula but has spread to all continents except Antarctica through the movement of humans and animals. Currently over 695 species of amphibians are known to be affected by the disease. Although the International Union for the Conservation of Nature has declared just 38 Species of amphibians as extinct, it is estimated that this number is actually over 150. The genus Atelopus, or harlequin frogs, is amongst the worst hit with over 30 of the 97 species presumed extinct. This genus is threatened because they live in the cool climate of the tropical Andes, at temperatures where the chytrid fungus does specifically well. They also breed in streams, another trait which has been linked with susceptibility to chytrid. But all is not lost. Recently, small populations of surviving species have been rediscovered, such as the variable harlequin frog and the Rio Pescado harlequin frog. Scientist believe that there must be something that allows these few individuals to persist in low densities at specific locations.

So we set out to Ecuador aiming to establish if the Podocarpus harlequin frog is still persisting at its remaining site in Yacuri National Park. If it was, we wanted to explore the threats to the species and suitable conservation actions. Finally, we wanted to compare the bacterial and fungal communities at this site with sites where the species is not present. The last goal will help us determine whether there is something in their environment that provides resistance to this remaining population.

Before we headed into the field, we did a presentation of our previous research on amphibian captive breeding programmes and the chytrid fungus at a university in Guayaquil in Southern Ecuador (UEES). We were hoping to create awareness of the amphibian crisis among local aspiring biologists, and to get locals excited about our project. This fits in perfectly with my work at Durrell, where I am developing guidelines based on my Master’s thesis and communicating my findings. Ecuador is home to over 580 species of amphibians, the third highest number after Brazil and Colombia, so it is a great place for me to share my lessons on amphibian captive breeding programmes.

Then, we headed off to our field sites where we took soil samples and swabs of 95 amphibians different elevations. The swabs will be analysed in a laboratory run by chytrid expert Matt Fisher at Imperial College London. Each habitat we went to was completely different from the previous one, which explains Ecuador’s incredible diversity in species. We had a great time exploring all the frogs we found along the way, compromising of 20 different species.

The end of our trip – Yacuri National Park – was the highlight. It took us five hours to hike to a small hut on the slope of a mountain, an hour away from the nearest lagoon. We spent the next two days in this remote, windy paramo landscape, searching for the Podocarpus harlequin frog. On the first day we had bad luck and the weather was not suitable for frogs to be out. We returned to the camp empty-handed and with a sense of defeat. The following day, we searched even harder, but were worried the story would repeat itself. Then, Phil came up to me with a frog in a bag and a mysterious expression on his face. He found one! We were ecstatic to be looking at just the fourth Podocarpus harlequin frog to be seen since 1994. Locals told us that they used to see these frogs dotted around the landscape, but within our lifetime they have disappeared from this largely untouched landscape. The chytrid fungus and climate change are the usual suspects, but we realised that this stream-breeding frog is now also challenged by introduced trout, which predate on the tadpoles of the resident amphibians. Therefore, it’s reassuring to know that the species is still hanging on to existence.

We found a few more amphibians in Yacuri to test for the chytrid fungus, and then packed up our gear and headed home. I am now back in the office, sharing all my travel stories with my colleagues. I hope that our results will become useful in the search for solutions to conserving species affected by the chytrid fungus. I also hope that 20 years from now, you will still be able to see Atelopus podocarpus at the top of Yacuri. In the meantime, I’m excited to wrap up all my projects with Durrell and move on to new things.