Smilisca phaeota

Masked Tree Frogs are a common sight in Drake Bay, and very often they are heard before they are seen.

Their common name comes from the black patch that starts at the tip of the snout and continues through the eye and the eardrum, along the frog's face. This black mask will enhance the frog's camouflage by hiding the shape of the eye, which is what many predators will use to detect their prey. They can change their color and you may find frogs with coloration ranging from light tan to olive green.

When Masked Tree Frogs are breeding, males can be found at nighttime calling from mud puddles or swampy areas and also, quite reliably, at La Paloma Lodge's swimming pool.

At this point, the frogs will mate. The female will lay up to 2000 eggs as the male fertilizes them. The eggs float on the surface of the water and will normally hatch within the next 24 hours.

Once the tadpoles hatch, they will develop in their puddle until metamorphosis is completed. This normally takes between 60 and 80 days. Because they develop in puddles that may dry out if there are several days without rain, the tadpoles are quite resistant to dehydration. They may survive up to 24 hours out of the water. During this time, they will hopefully get some rain and their puddle will fill up again.

After mating, couples will remain in amplexus for some time and we regularly see amplectant pairs moving through the vegetation. The pair photographed here was on a vine about two meters above a stream. As with most frogs, females are larger than males and in this species they seem to be quite responsive.

Once on a Night Tour, we encountered a large female perched in a tree about three meters off the ground. While explaining a little about the Masked Tree Frog's natural history, I imitated their call. Much to my chagrin, and our tourists' amusement, she leapt from her perch and landed directly on my chest!

Masked Tree Frogs inhabit Humid Lowland Forests throughout the Pacific and Caribbean regions of Costa Rica. They are absent from the much drier Guanacaste Province, in the northwest of the country.

Masked Tree Frogs are known to exist in Honduras, Nicaragua, Costa Rica, Panama, Ecuador and Colombia.

References:

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