** ADVANCE FOR SUNDAY, APRIL 1 ** FILE ** A coqui frog sits on a tree branch in El Yunque rainforest in Caimito, Puerto Rico, Feb. 14, 2002. The tiny frog is named coqui after its distinctive two-note call of "ko-KEE, ko-KEE," and has become a symbol for the island, its culture and its people. Researchers in Puerto Rico blame climate change for the declining of the species in Puerto Rico and nearby islands. (AP Photo/Gerald Lopez)