Variable Harlequin Toad (Atelopus varius)

The variable harlequin toad, also called the Costa Rican variable harlequin toad or clown frog, is a small true toad in the family Bufonidae that historically ranged across the Pacific and Atlantic slopes of the Cordillera de Tilaran in Costa Rica into western Panama, at elevations from 6 to 2,000 meters. Its skin carries the neurotoxin tetrodotoxin beneath conspicuous, aposematic coloring that warns predators of its toxicity. A population near Monteverde fell from about 751 adults in the early 1990s to none within a few years, and the species was believed extinct in Costa Rica by 1996 before being rediscovered there in 2003. It is now assessed as critically endangered by the IUCN, surviving only in scattered populations near Quepos, Costa Rica, and in western Panama, its decline driven chiefly by a chytrid fungus linked to broader climate pressures.