Amphibians
Golden Toad
Incilius periglenes · also called golden toad, Monteverde golden toad, orange toad, sapo dorado
The golden toad was a small, impossibly bright orange toad that lived in one patch of Costa Rican cloud forest and nowhere else. It was found in 1966, seen in its thousands as late as 1987, and then, within two years, it was gone. It has become the poster animal for the global collapse of amphibians.
Overview
Golden toads lived only in about 4 square kilometres of high cloud forest on the Monteverde ridge in northern Costa Rica, at around 1,500 m. Adults spent almost the whole year underground, emerging for only a few days of explosive breeding in shallow rain-fed pools. Males were a uniform, glowing tangerine orange; females were dark with scarlet-and-yellow blotches.
The collapse
In 1987 an observer counted about 1,500 toads. That year an unusually warm, dry El Niño lifted the cloud base and dried the breeding pools before the eggs could hatch. Only 10–11 toads were seen in 1988, a single male on 15 May 1989, and none ever again.
Why it vanished
The likely cause is a combination: warming and drying at Monteverde (linked to climate change) that stressed the population, plus the amphibian chytrid fungus then sweeping through Central America. The golden toad is often cited as one of the first extinctions attributed to climate change.
Status
The golden toad is Extinct, declared so by the IUCN in 2004 after years of fruitless searching.
Golden Toad: common questions
What did the golden toad look like?
The males were the striking ones — small toads, about 5 centimetres long, of a uniform, intense, almost fluorescent orange, so bright and glossy that they looked enamelled or dipped in paint, with no markings at all. Females were so different that early observers were unsure they belonged to the same species — larger, dark olive to black, and boldly marked with scarlet blotches each outlined in yellow. This extreme difference between the sexes is unusual among toads. The vivid orange of the males has made the golden toad an enduring visual symbol of amphibian decline, appearing on posters, book covers, and conservation logos.
Why did the golden toad go extinct?
There is no single agreed cause, but the pieces fit together. The golden toad existed only in a very small area of high-altitude cloud forest and depended on temporary pools that filled with rain and mist. In 1986–87 a strong El Niño event brought unusually warm, dry weather to Monteverde; the cloud bank that normally bathed the ridge lifted, the mist and rain that fed the pools failed, and the pools dried before the tadpoles could develop. Almost the entire 1987 breeding effort was lost. At the same time, the amphibian chytrid fungus (Batrachochytrium dendrobatidis) was spreading through the highlands of Central America and wiping out frog and toad populations, and it is thought to have finished off the drought-stressed, already tiny golden toad population. Because the warming and drying at Monteverde have been linked to human-caused climate change, the golden toad is often cited as one of the first species whose extinction was attributed, at least in part, to climate change.
When was the golden toad last seen?
The last confirmed sighting was of a single adult male on 15 May 1989, by biologist Martha Crump, who had studied the population through its collapse. Before that, only 10 or 11 individuals were found in 1988, down from an estimated 1,500 in 1987. Herpetologists and volunteers searched the Monteverde area intensively through the 1990s and 2000s, checking the old breeding pools every rainy season, but no golden toad was ever found again. The IUCN formally listed it as Extinct in 2004. It remains one of the very few amphibians for which extinction has been formally declared rather than the species simply being lost to view.
Is the golden toad related to the Panamanian golden frog?
Only distantly, and the shared name is misleading. The golden toad (Incilius periglenes) is a true toad in the family Bufonidae, from Costa Rica. The Panamanian golden frog (Atelopus zeteki) is a harlequin toad, also in the Bufonidae but a different genus, from the mountains of central Panama, and although it is called a "frog" it is technically a toad too. Both are (or were) small, brilliantly coloured cloud-forest bufonids that suffered catastrophic declines linked to the chytrid fungus and habitat change. The Panamanian golden frog is now considered Critically Endangered and possibly extinct in the wild, surviving in captive-breeding programmes, while the golden toad is simply gone.