The Waxy Monkey Tree Frog produces its own sunscreen to survive the intense tropical sun.

The Waxy Monkey Tree Frog (Phyllomedusa sauvagii) is native to the Chaco region of South America, spanning parts of Argentina, Bolivia, and Paraguay. This area is known for high temperatures and low humidity, which are typically lethal to moisture-dependent amphibians. To combat this, the frog possesses specialized cutaneous glands that secrete a complex mixture of lipids and proteins. Research published in the Journal of Experimental Biology has detailed how these frogs perform a complex grooming ritual. Using their limbs in a specific sequence, they spread the secretions from their neck glands across their back, belly, and toes. This process creates a highly effective physical barrier against evaporative water loss. Studies have shown that this wax coating reduces water loss to a rate comparable to that of desert reptiles. Without this protection, the frog's permeable skin would lose moisture rapidly in the 100-degree Fahrenheit heat of the Chaco. Additionally, these secretions contain antimicrobial peptides that protect the frog from infections while it basks in direct sunlight. This evolutionary trait allows the frog to remain active during the day and occupy high tree canopies where sunlight is most intense. By mimicking the water-retention strategies of reptiles, the Waxy Monkey Tree Frog has successfully carved out a niche in one of the harshest environments on the continent.