While on a night hike in Costa Rica I spotted a faint reflective eye shine from a tree frog about eight meters high on a Welfia-like palm. 99% of the time the eye shine belongs to a red-eyed tree frog (Agalychnis callidryas), but I was thrilled to notice the distinct lateral tiger stripe pattern peeking out from the leafy green body. Just as a friend caught up to me I pointed the frog out, and he also initially dismissed it as an Agalychnis. After lowering the palm stem we were able to see the frog more closely and confirm it as a young Sylvia’s tree frog (Cruziohyla sylviae, described this year as a distinct species from C. calcarifer). All three species of Cruziohyla are easily distinguishable from other tree frogs by cryptic leaf-like dermal folds on the appendages, a dazzling yellow-orange ventral coloration, and a unique bicolored iris. The amazon fringed tree frog (Cruziohyla craspedopus) also sports a mottled galactic dorsal pattern perhaps resembling lichen along with more elaborate fringing on the hind limbs. Cruziohyla are uncommonly spotted due to their arboreal habits. They only descend from the canopy to breed exclusively in water-filled tree holes, with the eggs eventually hatching and falling into the water below as tadpoles.
Photographed after disturbance [4] unless otherwise stated
