The Rancho Grande harlequin toad (Atelopus cruciger) is one of ten described harlequin frog species in Venezuela and the only one with currently known stable wild populations. Following a severe decline in the late 1980s, the species is now restricted to a small portion of its historical range and remains classified as Critically Endangered. This project supports the first release of captive-bred individuals as part of a long-term conservation programme aimed at restoring populations within the species’ historical distribution.

Since 2022, a coordinated conservation effort has established a captive assurance colony that currently produces several hundred individuals per year for conservation purposes. The present phase focuses on the release of post-metamorphic individuals, including juveniles and adults, into selected sites within the historical range where suitable habitat conditions persist.

Given the challenges of population establishment after release, the project integrates controlled releases with post-release monitoring to assess survival, health, and site use during the initial stages. Monitoring protocols are designed to generate data to inform adaptive management and guide subsequent reintroduction efforts.In parallel, the project includes capacity building through the training of local personnel in population monitoring, threat detection, and habitat protection, supporting the continuity of conservation actions beyond the duration of the project.

The species is associated with clean, fast-flowing montane streams, and its conservation contributes to the protection of freshwater ecosystems that are also important for local communities.

As reintroductions of Atelopus species remain limited, this project will generate data to evaluate reintroduction protocols and inform future recovery actions.