 Declines in amphibian populations were first widely recognized in the late 1980s , when a large gathering of herpetologists reported noticing declines in populations in amphibians across the globe . Among these species , the Golden toad ( Bufo periglenes ) endemic to Monteverde , Costa Rica , featured prominently . It was the subject of scientific research until populations suddenly crashed in 1987 and it had disappeared completely by 1989 . Other species at Monteverde , including the Monteverde Harlequin Frog ( Atelopus varius ) , also disappeared at the same time . Because these species were located in the pristine Monteverde Cloud Forest Reserve , and these extinctions could not be related to local human activities , they raised particular concern among biologists . 
