- Issue: Spring 2018
If you’ve ever been annoyed by the cost of sunscreen, you might envy the waxy monkey tree frog. Found in the dry scrub forests of South America’s Chaco region, this portly little amphibian spends most of its life in the treetops, where it snoozes for hours in the hot sun. Most frogs can’t tolerate prolonged sunbathing; it would dry out their porous skin, which needs to stay moist. But Phyllomedusa sauvagii produces a waxy substance that covers its skin with a protective layer—basically, frog sunblock.
WAXY MONKEY TREE FROG
Range Dry Chaco forests of eastern Bolivia, northern Paraguay, Mato Grosso do Sul (Brazil), and northern Argentina
Habitat Trees and other plants near temporary lagoons and ponds
Diet Primarily insects
Threats International pet trade; destruction of Chaco habitat in Argentina and Paraguay for agriculture and logging
Eggs The eggs are folded into a large leaf suspended over a pond or lagoon. When they hatch, the tadpoles drop down into the water and begin growing.
Deamorphin The frog’s secretions contain dermorphin, a unique natural opioid that’s 40 times stronger than morphine. In recent years, a synthetic version of the chemical has been used illegally in the US as a powerful performance-enhancing drug for racehorses.
Prehensile Hands with Opposable Thumbs
The frog’s well-adapted hands are used for gripping tree branches and helping it to walk, rather than hop, through its treetop habitat (hence the “monkey” in its name).
The frog uses its incredibly flexible back legs for walking through the treetops and spreading the waxy secretions over its entire body.
Using its feet, the waxy monkey tree frog spreads lipids from glands in its skin by a series of dexterous movements.
Illustrations © Katie Scott/WWF-US