October 06, 2015

By Mark Wanner
Zoological Manager of Herpetology

Photos: Luis Coloma, Ph.D., Director of Centro Jambatu in Ecuador

Recently 44 frogs, including 10 Anthony's poison frogs and 10 Sun's glass frogs, arrived in St. Louis to make the Zoo their home. The gorgeous blue-striped poison frog and the transparently emerald green glass frog have never before been at the Saint Louis Zoo. All these newcomers are from Ecuador, and all are captive-born.

This breeding process isn't all that easy. Watching the translucent eggs develop into tadpoles is amazing. The morphing of tadpoles into froglets and finally into adults is magical, but it takes intense work, dedication and expertise to breed a successful frog colony. Keeping the species alive is also demanding.

Ecuador once was teeming with frogs on the shores of its rivers. Ecuadorian amphibians still represent nine percent of global amphibian diversity. Estimates are that Ecuador had over 700 frog species—a wellspring of amphibian richness. Unfortunately, at least 30 percent (156 species) are threatened with extinction, and among them, 16 species are now possibly extinct.

What is killing the frogs? Pathogens like amphibian chytrid fungus (a disease killing massive numbers of amphibians) are among a cocktail of factors behind their loss. However, in Ecuador, increasingly it seems climate change and habitat loss are the real culprits.

Let's take climate change: Scientists believe that a warming climate may play an indirect role in facilitating epidemics of infectious disease. Changes in climate can affect survival, growth, reproduction and dispersal capabilities of animals. Climate change can also alter amphibian habitats, including vegetation, soil and hydrology, and can influence food availability and predator-prey relationships.

Another, even more immediate problem frogs face is habitat loss, which is the result of what humans are doing. There are over six billion humans on the planet but not nearly enough natural resources to support us in a sustainable manner at our current rate of consumption. Humans alter and destroy amphibian habitat by logging forests, draining swamps, building over areas that once had streams, damming and draining rivers for irrigation, using pesticides/herbicides and introducing weeds and livestock.

What are we doing to combat the decline of these creatures that are such important sentinels of ecosystem health? Our Zoo is supporting the research and conservation work of Centro Jambatu for Research and Conservation of Amphibians (Otonga Foundation) based in Quito, Ecuador. Luis Coloma, Ph.D., who directs Centro Jambatu, is working to develop methods of cryopreservation of amphibian germ cells so that we can continue to breed amphibians in captivity even after they are extinct for possible reintroduction in the wild, when habitats are available. For several years, I have worked in Ecuador with Dr. Coloma and his staff to collect endangered frog species.

Amphibians are one of the first animals to suffer when there are changes in the ecosystem. Since they live on both land and in water and their bodies are permeable, they are sensitive to problems in both environments. This is why they are called a bellwether species. It is important to our health and the health of our planet that we save them.