The lemur leaf frog is the smallest of the Costa Rican Leaf Frogs, with females being larger than males at a typical length of 30-45mm. Their colour ranges from bright yellow-green during the day to red-brown at night and within different populations they may also have dark flecks on their dorsal surface.
Their eyes will also change colour from day to night going from a silvery gold to purplish grey or brown colour at night surrounded by a black ring. They have large eyes with a vertical pupil however unlike some other Agalychnis, the lower eyelid is not reticulated.
Lemur Leaf frogs sleep during the day on the underside of leaves and are active at night leaving their daytime resting places to hunt for food and reproduce. They will produce a call that consists of a series of single, short “ticks” to attract a mate. More rapid encounter call and release calls are used to warn off other male competitors often escalating to aggressive grappling with other male opponents.
The breeding sites of the lemur frog are leaves overhanging pools or slow moving streams. Egg masses are laid on the surface of leaves in similar fashion to other members of the genus.

IUCN Red List status: Critically Endangered.
Listed as Critically Endangered because of ongoing drastic population declines, estimated to be more than 80% over a ten year period, probably mostly due to chytridiomycosis, a fungus decimating amphibian populations globally.