Wildlife monitoring at Las Chutas

The road from San Gerardo to the Caño Negro River

The area known as “Las Chutas” is on a ridge in the CER, northeast of the town of Monteverde, south of Arenal Volcano, west of the Peñas Blancas Valley, and east of San Gerardo biological station.  Forty years ago, the portion of the Caribbean slope of the Tilaran mountain range now part of the CER was largely deforested for pastureland, particularly in the valleys.  The less accessible ridges and hilltops retained more of their tree cover, but clearings speckled the highlands.  Since the CER purchased farms during the past few decades, the forest has regenerated significantly.  Now, to get to a pasture or cleared area from Las Chutas, you have to hike for more than two hours.

Caño Negro River
The camp used during frog monitoring expeditions. It is located 3 hours by foot from the San Gerardo station.

What makes Las Chutas noteworthy, aside from its isolation and dense vegetation, is that it is a site where two species of frog presumed extinct have reappeared.  In the past decades, there has been a worldwide decline in amphibians.  Possible causes include infestations of chytrid fungus, increased UV radiation, and climate change  (http://onlinelibrary.wiley.com/doi/10.1046/j.1472-4642.2003.00012.x/full).  During the 1980s, multiple frog populations disappeared from the Monteverde region, including the harlequin frog, green-eyed frog, lichen stream frog, and the famous golden toad.

In 2002, the green-eyed frog (Lithobates vibicarius) reappeared in the CER.  Just this past March, the lichen stream frog (also known as Starrett’s tree frog) was re-discovered in a stream in Las Chutas.

The Green-eyed Frog (Lithobates vibicarius syn. Rana vibicaria) Photo credit: Luis Solano

Two small ponds surrounded by ferns, palms, heliconias, aroids, and moss-covered trees serve as important breeding grounds for the green-eyed frog.  The frogs lay hundreds of eggs in puddles in the forest, and when the tadpoles hatch, they migrate to the ponds.

One of two ponds at Las Chutas, this is an important breeding site for the green-eyed frog.


Eladio Cruz, MCL member, and Luis Solano, head of maintenance, search for frogs along a stream

On a monthly (sometimes bi-monthly) basis, Luis Solano makes the trek to Las Chutas to monitor frog populations.  He conducts five, 50-meter-long transects in which he counts every Green-eyed Frog that he sees.  At night, he searches for all types of frogs, notes their presence by sight or sound, and swabs some of them to test for chytrid fungus growing on their skin.  In addition to frog monitoring, Luis is in charge of maintenance in the CER, spending many hours cleaning trails and boundary lines.

Emerald Glass Frog (Centrolenella prosoblepon)


Lichen Stream Frog (Isthmohyla tica)
Lichen Stream Frog (Isthmohyla tica), listed as critically endangered on the IUCN red list
Bare-hearted Glass Frog (Hyalinobatrachium colymbiphyllum)
Why it's called a glass frog...
Eladio Cruz balances precariously on a log, having collected various species of dragonflies in the middle of the pond. Photo credit: Francis Joyce

Eladio Cruz is another person who has done a lot of fieldwork in the CER.  His most recent project is collecting specimens for an inventory of the dragonflies and damselflies of the Monteverde region.  The Las Chutas ponds proved to be productive places to collect.  When the sun emerged from behind clouds, upwards of six species of dragonflies and damselflies began to whiz above the pond, some mating, some hunting, and some laying eggs in the water.  They flashed metallic blues, greens, and reds from their bodies, tracing ovals and spirals in the air.  To gain a sense of diversity and beauty of these insects, check out this website:Dragonflies and Damselflies of Costa Rica.

One of the many fungus species in the CER, Hygrocybe sp.


Trevoria glumacea, a fragrant, pendant orchid

The Children’s Eternal Rainforest and the Monteverde Conservation League have saved many species from both local extinction and total extinction.  No doubt the green-eyed frog and the lichen stream frog are only a few representative organisms of the biodiversity that the CER has rescued.

A farm bordering the Children's Eternal Rainforest.
A tangle of barbed wire attests to this piece of forest's previous life as pasture.






By guest blogger Richard Joyce.

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