Golden toad  (Bufo periglenes)

The population of golden toads underwent a massive crash in 1987 (2). A few individuals were found up until 1989, but the species has not been seen since then (2). Twenty out of 50 species of frogs and toads (anurans) occurring within a 30 kilometres squared area in Monteverde disappeared after synchronous population crashes in 1987, and have shown no sign of recovery (4). The area is pristine and free of direct human influences (5), a number of reasons have been proposed to explain the decline, including fungal disease, and climatic changes (4) (7).

The probable extinction of the golden toad reflects the current worldwide decline in amphibian populations. The more subtle effects of human activities on the world's ecosystems such as the build-up of pollutants, the decrease in atmospheric ozone, and changing weather patterns are beginning to take their toll. Amphibians may be our first and only early warning that these effects are starting to reach catastrophic levels (6), and may be the first sign of impending ecosystem crashes (7). In 1991, the Species Survival Commission of the IUCN established the Declining Amphibian Populations Task Force (DAPTF), which later merged into the Amphibian Specialist Group, which aims to raise money and promote research into the global amphibian decline (6).