Species Data

Class: Amphibia

Order: Anura

Family: Bufonidae

Scientific Name: Osornophryne simpsoni

IUCN Red List status: Not Evaluated



Simpson’s Plump Toad was first discovered in 2011, in Fundación EcoMinga’s Río Zúñac Reserve. The species is named in honour of Dr Nigel Simpson, one of EcoMinga’s honourary directors and a current member of the World Land Trust Council.

Osornophryne simpsoni is distinguished from other Osornophryne species by its short, rounded snout, the conical pustules on its flanks, and its fourth and fifth toes (which are longer than its other digits). The toad’s colouration is dark or light brown, with orange to yellow flanks, and a cream-yellow throat.



Plump toads (Osornophryne) are found only in the Andes Mountains of Colombia and Ecuador, living high up in forest and páramo habitats at elevations between 2,100 and 4,000 metres.

In the upper Río Pastaza watershed – the base of EcoMinga’s operations – our partner has identified a number of unusual amphibians whose distribution correlates with unusual orchids. As elevations increase, one finds a dramatic change in the number of locally endemic species present. Simpson’s Plump Toad, to date found only in Río Zúñac and the surrounding area, is just one example of this phenomenon.

As all other plump toads are known to have a restricted distribution, it is likely this species is found nowhere else on Earth.

Simpson's Plump Toad

Threats and Conservation

Although enough Osornophryne simpsoni specimens have been collected to describe the species and add it to the scientific canon, this toad remains elusive. Every individual to date has been found at night, clinging to fern and bromeliad leaves, but apart from this not much is known about its behaviour. What is known is how vulnerable the species is to habitat loss and fragmentation.

Simpson’s Plump Toad is one of almost 100 species discovered in the upper Río Pastaza watershed since EcoMinga began working in the area since 2007. Almost all of these species are restricted entirely to the watershed, many of them with very small home ranges.

WLT’s Life on the Edge appeal aims to protect some of the most threatened endemic life in the watershed – like Simpson’s Plump Toad – by expanding the Río Zúñac and Río Anzu reserves. Donations to the appeal will protect forests that would likely be cut down for timber, cattle pasture, cash crop plantations, or oil extraction projects if we do not act in time.


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