acrylic on illustration board 20” x 15” During the dry season, over 100 populations of Varied Harlequin Toads (Atelopus varius) once congregated along forest streams in Costa Rica and western Panama to breed. Cloaked in a wide variety of colors and patterns, these beautiful amphibians ranged from cream to lemon yellow, to lime and scarlet, or various combinations of these base hues, splotched or barred with brown, green or black. Ranging in length from one to two inches, the males averaged about a quarter smaller than females. Their gaudiness was probably a case of aposematic, or warning coloring, as their skin contained quantities of the toxic alkaloid tetrodotoxin. In the late 1980s most populations began a steep decline, beginning in central Costa Rica. The Panamanian frogs didn't start to crash until about 1992. The causes of this crash are still poorly understood, and the subject of some controversy, but the insidious chytrid fungus Batrachochytrium dendrobatidis plays an important role. How, and even whether Bd, as the fungus is commonly known, kills frogs still is a mystery, but circumstantial evidence is accumulating that points to it as the direct cause of much global frog decline. The Varied Harlequin Toad and other members of the genus Atelopus appear to be quite susceptible to Bd, and of the 120 or so species, some 60% are believed to have recently gone extinct in the wild. Wild populations of A. varius were feared extinct, but a small population near Quepos, Costa Rica, discovered in 2003, perseveres. Incidental species include a leaf-cutter ant (Atta sp.), the butterfly Morpho amathonte, a Cloud-forest Anole (Anolis tropidolepis) and a Blue-gray Tanager (Thraupis episcopus). |
