Agalychnis callidryas

There is probably no better ambassador for Costa Rica, and for Tropical Rainforests in general, than the Gaudy Leaf Frog. Their bold and vibrant color patterns make them one of the most photographed frogs in the world.

Along with Toucans, Parrots, Monkeys and Quetzals, these very attractive amphibians have come to embody the beauty and wonder awaiting discovery in the Costa Rican Rainforest. There is hardly an item in any souvenir store which is not decorated with its image: t-shirts, beach towels, calendars, hats, stuffed animals, shot glasses or any other item imaginable.

Yet, the moment you see this frog in person, the reason it fascinates observers and why it is such a sought after model for photographers becomes strikingly obvious. It truly has a charm all its own.

Gaudy Leaf Frogs are primarily lowland frogs and can be commonly found throughout the Caribbean Lowlands and the humid lowlands of the Pacific Slope from sea level to about 1000 meters in elevation. They are not found in the drier parts of the Guanacaste Province, but have recently been collected on the southern most tip of the Nicoya Peninsula. Their size ranges from 50 to 71 millimeters, females being larger than males.

There are two distinct, geographically isolated, populations in Costa Rica. Although they are still considered the same species, frogs living on the Caribbean side have much brighter coloration. These individuals normally have bright orange hands and feet as well as bright blue along their sides. Their upper arms are normally either bright blue or orange. The intensity of the colors and their pattern make these Caribbean frogs truly gaudy specimens.

The coloration of Gaudy Leaf Frogs in Drake Bay, and throughout the Pacific Slope, is a bit muted. Their fingers and toes may have greenish, cream or light orange coloration and their sides are normally a much lighter blue or brownish in color. Still, they remain a spectacle to behold and invariably bring a gasp and a smile to everyone's face when encountered on The Night Tour. All of the frogs featured on this web page are wild individuals photographed in Drake Bay.

Because of their arboreal and nocturnal lifestyle, Gaudy Leaf Frogs are not so easily encountered by travelers. During dry season, as well as throughout the day, they all but disappear into the forest canopy. Very little is known about their activity during these times. On the Pacific, because there is a pronounced dry season, we only tend to see them during the rainier months. Breeding season normally begins in late May or early June and this is when males descend closer to ground level and embark on their quest to find a mate.

Activity usually peaks on rainy nights, sometimes before or after a heavy rain. Generally males will call in groups near a breeding site. Calling males will try different perches, facing different directions throughout the night in an effort to improve their chances of attracting a female. A gravid female will sit and listen to the calling males until she decides on one she likes.

Once in amplexus, the female will descend to a body of water, carrying her mate on her back, and fill her bladder by absorbing

The eggs are transparent and the little embryos can be observed as they grow. As they develop, they will take on a darker brown color and frequently move around inside their egg. They will finish their development in about five to seven days.

Normally, during a heavy rain, the little tadpoles will wiggle free of the egg mass and will hopefully find their way into a temporary pool where they will complete their metamorphosis.

By laying their eggs on leaves and completing their tadpole stage in temporary pools, rather than rivers or streams, Gaudy Leaf Frogs bypass the predators responsible for the highest egg and tadpole mortality: fish. Still, their eggs are preyed upon by Northern Cat-eyed Snakes  (Leptodeira septentrionalis) and Yellow Chunk-headed Snakes (Imantodes inornatus). Northern Cat-eyed Snakes, which are frog specialists, will also prey on adult frogs.

After the tadpoles leave the egg mass and reach a temporary pool they will complete metamorphosis in about 80 days. Because their development takes place in temporary pools, tadpoles are quite resistant to dehydration and may live up to 20 hours out of the water. This way, if their puddle dries up, they may be able to survive until the next heavy rain refills it.

Once the little frogs leave the water, it will take them about a year to reach adult size. Very little is know about the activities and behavior of juvenile frogs.

Gaudy Leaf Frogs can change their skin color and typically have their day time and night time colors. They have a light green color during the day and while they are at rest. After they become active at night, their skin normally turns a darker shade of green.

Like most frogs, Gaudy Leaf Frogs posses skin toxins. Frogs belonging to the Phyllomedusine Subfamily, as Gaudy Leaf Frogs do, have a very unique blend of toxins including two substances not found on the skin of any other amphibian on earth. Although they are not nearly as irritating as many other Costa Rican frogs, special care should always be taken when handling them. There are some frog species that should never be handled by anyone besides trained professionals.

A frog collector in Costa Rica handled several Gaudy Leaf Frogs and later smoked a cigarette without washing his hands. The toxins passed on to his cigarette and he then inhaled them. This resulted in coughing fits and a general discomfort that lasted for an entire day. When handling any frog, it is always important to wash your hands before and afterwards. Washing them before will protect the frog from absorbing any substances that you may have on you hands. Washing them afterwards will protect you from the toxins present on the frog's skin. Even after washing your hands, it is a good idea to refrain from touching your mouth, eyes and nose. Small frogs should be handled sparingly, since just your body heat may be enough to make it overheat and kill it.

References:

Beletsky, L.  2005  Travellers' Wildlife Guides Costa Rica  Interlink Publishing

Kubicki, B.  2004  Leaf-frogs of Costa Rica  Editorial INBio

Leenders, T.  2001  A Guide to Amphibians and Reptiles of Costa Rica  Zona Tropical

Savage, J.  2002  The Amphibians and Reptiles of Costa Rica   University of Chicago Press