Fieldwork Fun

We woke up in Zamora to a drizzle, feeling really hopeful that the rain would bring out more frogs for us to sample. Before I continue, Phil is going to give a brief description of the work we’re trying to do, and why:

Habitat and environmental conditions play a huge role in the impact of the chytrid fungus on amphibian populations. Species living in cool, high elevation habitats, such as the Podocarpus stubfoot toad are disproportionately affected by the disease. Rapid declines in Ecuadorian amphibian populations due to chytrid started in the 1980s. Since then, many species have become extinct or have persisted in very small populations which have been unable to repopulate what appears to be pristine habitat where they once occurred. We are interested in how this critically endangered species has continued to survive in this location while remaining absent throughout the rest of its historic range. Another important factor in the disease resistance of amphibians is the microbial community living on their skin. Certain species of bacteria have been shown to inhibit the amphibian pathogen Bd and confer resistance to the host. We are particularly interested to see if there are differences in microbial community structure between disease-resistant and disease-susceptible species. To do this, we intended to swab amphibians from Zamora (1000 masl), where the amazon basin meets the Andes mountains, to the Paramo of Yacuri (3500 masl) which provides a last refuge to the critically endangered Podocarpus stubfoot toad. This altitude gradient will give us a range of temperatures, amphibian species and habitat types to compare disease prevalence in different climates.

With these targets in mind, we set off to the field. We started by driving down a road towards Podocarpus National Park entering by foot. Although it had rained a bit, the place was quite dry and the trails too modified for amphibians so we went home with just a few captures. We returned during the night and searched along streams we had located during the day. The guards had triple warned us that a lot of snakes were out at the moment, so we looked carefully before every step. Still, returning the same way we came from, Freddy enthusiastically pointed out an absolutely stunning, but also extremely venomous juvenile viper coloured with yellow and black. The viper was right were Phil had put his foot on the way up! In spite of the apparently suitable habitat, we were less fortunate on the frog front. This became somewhat a theme of the fieldwork along with a curse of bad weather. We spent two nights and two days looking for amphibian species near Zamora, and found just one of the super common and widespread cane toads. We were a bit more lucky with two species of hylids, Dendropshophus sp. And Boana fasciatus, and got the number of swabs we needed (to test them for chytrid fungus). These hylids were beautiful small frogs in creme and yellow, the Dendropsophus with dark spots. We left Zamora, hoping for better weather and more frogs as we were starting to worry.​

The next day we got ready to go into the field and drove on the road we came from, stopping off at a research station called San Francisco. We parked the car and followed a trail to a stream where the last known individual of Atelopus nepiozomus was found in 2010. We decided to give it a go, and looked for other amphibians as we made our way up the river until we got to a waterfall which Phil unsuccessfully decided to climb. Again, to our avail, we found only one individual; a Pristimantis. We then continued to Loja, a bigger city West of Zamora. After eating a slice of sweet pizza at a colonial city square and checking into a hostel, we continued to meet up with some local herpetologists, Diego, Paul and Diana. All of us headed back to the river at San Francisco to give it another go, but had little more luck finding just two more Pristimantis. Climbing all the rocks in the river left a few of us with wet wellies, and one of us made it fully into the river. Disappointed by another poor night, we headed off to a different site nearby based on recommendations by Diego, Paul and Diana, who had to return home. With limited instructions, we made it onto some trail which might or might not have been the right one. We walked quickly along the trail until we decided we had gone far enough and would search on the way back. Walking slower, I could suddenly see that the trail consisted of something like a mix of landslide and wilted vegetation nested on top of roots overhanging steep, forested cliffs. At one point, I noticed that Phil and Freddy were no longer behind me, and waited for a bit. They both came strolling back looking fine, until Phil burst out that Freddy had slipped and Phil had to pull him back up. I was stunned that neither of them had let out any sound during this spectacle. Much more cautious about the trail ahead, we spent a good few hours searching for more, finding just one additional Pristimantis. The area has been quite windy for a while, and even with some rain, the vegetation dried out quickly and the frogs had retreated into the leaflitter. We swapped the one frog and made it back to the hostel after three in the morning. The next day, we met up again with Paul who kindly took us to a private reserve called Madrigal del Podocarpus. The couple who run the reserve and a young student greeted us keenly and gave us coffee and humitas, a local delicacy made from corn husk. We conversed about the wildlife in the reserve, and the work of the locals for the conservation of the area. After a while, we were sent off with the young student, Marek, as our guide. We spent hours climbing a forested trail, which got steeper and more dense towards the end. The trail left us at the beginning of the paramo, an Andean tundra ecosystem. It was drizzling with rain and the wind was stronger than I had ever imagined, trying to push us over the narrow trails along the mountain ridge. The ground was covered with spikey bromeliads, a favourite food of the spectacled bear which regularly visits the area. We finally made it to a few lakes which were a bit more sheltered. We found Gastrotheca tadpoles in the lakes and swapped the ones we could catch for chytrid. On the walk back, we followed a more sheltered trail, but some of us were ill prepared for the strong winds and 7 degrees at the top, and had become quite cold at this point. Most of the frogs had disappeared, this time to shelter from the wind. To keep with tradition, we found one individual Pristimantis. We then got in the car and turned the heating on while desperately heading for a more sheltered site in hope of more frogs. This time we got lucky as Phil and Paul, the surviving members of the crew at this point, found five adult Gastrotheca.​

Just as the tide appeared to turn, a new crisis hit. Freddy, our much needed local herpetologist fell ill. We returned to the hostel feeling deflated as we realised our departure for Yacuri the following day would have to be postponed. Paul kindly offered to spend the following day with us, searching for frogs at a paramo site near a nearby village named Saraguro. It’s a unique Quechua village where the women were cow skin patterned hats and the men ¾ length trousers. After touring the city for a bit, we headed up to the site where we finally had more luck. We found three male Pristimantis and more Gastrotheca tadpoles to swab. We then went to the same site as the previous day and found another four adult Gastrotheca. We were finally starting to see the number of amphibians of different species that we needed. We headed back feeling good, and back at the hostel we established that Freddie would be able to drive us the following day to Amaluza from where we would begin our hike. Unfortunately, he was not feeling well enough to join the hike himself. The next morning, we were hit by more devastating news as the guide called and said that Yacuri was too windy for the climb. We were already one day short and the whole project seemed at stake. We got into the car and headed for Amaluza, not knowing what to expect when we got there. The rest of the project will follow in a couple of days.