Conservation Value:

The Sierra Nevada de Santa Marta (SNSM), classified as a Key Biodiversity Area, appears to be the only place in the Americas with stable populations of high-altitude harlequin toads — the world's most threatened genus of amphibians. The SNSM is home to 5 threatened endemic Atelopus species, including the Critically Endangered starry night toad (Atelopus arsyecue), the Endangered Santa Marta harlequin toad (Atelopus laetissimus), and the Endangered San Lorenzo harlequin toad (Atelopus nahumae). It is also home to 17 other endemic species of amphibians and at least 2 more species of Atelopus that are in the process of being described. The reasons these stable populations of high-altitude harlequin toads occur here are largely unknown.

Reaching 5,775 m, SNSM is the highest coastal mountain in the world.  Its elevational amplitude, isolation, and tropical location have conferred biological and hydrological importance. SNSM ecosystems encompass tropical dry forests (one of the most threatened ecosystems in the Neotropics), montane forests and páramos that supply drinking water to two million people in the departments (provinces) of Magdalena, Cesar, and La Guajira.

Threats:

Disease transmission by the Batrachochytrium dendrobatidis (Bd) fungus and habitat degradation due to livestock and agricultural activities, water pollution, and unsustainable tourism practices are the main drivers behind the extinction or endangerment of many harlequin toads (81% of Atelopus species are classified as Endangered or Critically Endangered).

Actions & Results:

Key actions are to assess and monitor the population dynamics and threats to endemic species of harlequin toads, and to design and develop conservation strategies with local communities. In 2023, 20 expeditions were carried out to collect demographic data on two harlequin toad species (Atelopus laetissimus and Atelopus nahumae). In addition, Fundación Atelopus is working toward increasing connectivity between forest patches through reforestation, negotiating restrictive land use agreements with farm owners to reduce impacts of grazing and deforestation in critical areas adjacent to breeding streams, and promoting community awareness.