Seeing Sirens with a Herpetologist

This post is part of an ongoing series about the investigation and documentation of the biodiversity of the Chontayacu valley in the Andean Cloud Forest in Ecuador.

It was early December. In Chontayacu, that doesn't mean much weather-wise - rainy as usual, and chilly at night if wearing short sleeves. We had invited Amanda Quezada, herpetologist, to come have a first look at the Chontayacu Reserve.

What is a herpetologist? A person who studies reptiles and amphibians.

And in the case of Amanda, a person who can dive into the forest underbrush and return with a snake in either hand. Someone who can identify a frog just based on the sound of its call, even find animals through sound. In sum, someone endowed with biological talents just short of a superpower.

Amanda was here for three days, getting to know the area and taking white-background pictures of specimens during the day, and taking night walks in the evening. I, a layman, came along for the ride, always excited to learn about nature.

The herpetologist and photographer at her makeshift studio.

Our goal was to begin to assess the herpetological biodiversity of Chontayacu. Colleagues had also already spotted and photographed specimens of the Siren Glassfrog (Nymphargus siren), so an almost equally important goal was to register more individuals and get a better sense of how common they were.

Nymphargus siren is a glass frog species, that is, a species of frog that is transparent. This adaptation allows them to camouflage, as their outline is more difficult to recognize against or through the foliage (especially at night, when they are active). It is endangered, and one of a group of species that contributed to the decision of making nearby Sumaco National Park being declared a Key Biodiversity Area.

For the uninitiated, Siren Glass Frogs are very hard to spot, but not to hear. Their distinctive chirp was the first and clearest clue before finding a group of them.

The first specimen we found, we heard. We were at a small creek that sloped steeply upwards, culminating in a craggy waterfall. We spent quite some time wading through the creek, looking for the frog on foliage by the water. As we neared it, we realized we had to look up.

The frog was quite far up into the canopy. Luckily, the path rose as it followed the creek, and as we continued, Amanda's eagle eyes spotted our little friend, perched on a leaf, about 2 meters off a ledge that led straight into the water!

(Casually, Amanda mentioned to me that the name siren refers to the call of the bird-women of greek mythology, those monsters that called sailors to their deaths. It is said that the frogs do the same for researchers: they sound enticingly close and then lead them to the perils of streams.)

To my amazement, Amanda handed me her snake hook and bag, stepped off the trail, and started side-stepping on the ledge, until she was about 2 meters in. I used the hook to help move the branches in her direction, and after a few tries, we had our first photograph.

A photo of our little friend. Photograph by Amanda Quezada

After this herculean effort, and as we continued to visit more creeks, we became more aware of the abundant Nymphargus siren population in the area. In the following days, we were able to find and photograph males making their mating calls, with their throats puffed up in a bubble, along with the eggs the males were tasked with caring for and defending. By the end of our three days, we were almost sick of seeing them.

A male Siren Glassfrog calls for a mate. Photograph by Amanda Quezada

A male Siren Glassfrog guards his eggs. Photograph by Frank Pichardo

Nymphargus siren is one of many endangered frog species. Amphibians are the most endangered vertebrate group in the world, with 41% of amphibians globally threatened with extinction. Infectious diseases like chytridiomycosis caused large-scale population losses starting in the 1980s. Continued habitat destruction is also a major threat, particularly as amphibians are very sensitive to clean waters.

Amphibians' thin skin helps them breathe and absorb water, but makes them very sensitive to contaminants. They are among the first animals affected by disturbances. The flip side of this sensitivity is that they have been likened to canaries in a coal mine - an early environmental warning. Amphibians are indicator species: robust populations indicate a healthy ecosystem.

Even in Chontayacu, the Siren Glassfrog is under threat: attempts to build an irrigation system have greatly disturbed some of the creeks they are found in. Continuing to work to restore these creeks, protect more land and reforest more of their habitat will be vital in helping preserve this little treasure of nature. And of course, the more we know and learn about it, the more we can do to save the cloud forest.

Stay tuned for our next installment of our herping adventures!