What does a frog hidden on top of a mountain reveal about the Atlantic Forest?

Crossodactylodes alairi sp. nov., holotype in life (UFMG-AMP 14201, male, SVL 21.1 mm).

Por: Gabriela Andrietta

A new species of frog has been described by researchers based on studies conducted in Forno Grande State Park, in Castelo, Espírito Santo. The discovery of Crossodactylodes alairi was published in the scientific journal Zoologica Scripta and reinforces the importance of highland forests as biodiversity refuges and priority areas for conservation.

Small in size, the little frog lives in bromeliads and depends entirely on them for shelter, food, and reproduction. Like other species of the same genus (Crossodactylodes), it has an extremely restricted distribution: it occurs in highland forest areas that likely acted as refuges, providing stable conditions for the survival of the species.

According to one of the study's authors, Dr. Marcus Thadeu T. Santos, affiliated with the laboratory of Prof. Dr. Célio Haddad, also an author of the study, the discovery was the result of more than a decade of work. "I carried out the first expeditions over 10 years ago. The specimen that caught my attention was collected in 1973 and was deposited at the Mello Leitão Biology Museum. I decided to organize an expedition to Forno Grande to try to find these animals in the field. Over the years, we expanded the sampling and used detailed morphological and genetic analyses," says the researcher.

In total, 10 genetic fragments and several morphological characteristics were analyzed. The study also used computational models to test hypotheses about the group's diversification processes. The results indicate that the origin of the new species is linked to habitat fragmentation caused by climate change during the Plio-Pleistocene (between 5 million and 12,000 years ago), a period characterized by significant climate change.

Forno Grande State Park has varying altitudes (from the base to the top of the mountains), which creates different types of vegetation and climates throughout the park. This creates many microenvironments—small spaces with unique characteristics—such as humid, cool, shaded, rocky soil, and other areas. This environmental diversity allows many different species to thrive there. According to Santos, "This favors the presence of a wide variety of plants and animals. Since few well-preserved fragments of the Atlantic Forest remain, many species depend on areas like Forno Grande to survive." Although the Atlantic Forest has been heavily deforested in recent decades, well-preserved mountainous areas, such as Forno Grande, become essential refuges for endangered species. Without these environments, many of them would disappear.

The name "alairí" pays homage to Alair Tedesco, a local resident who worked for 27 years as a park ranger at Forno Grande State Park and, even after retirement, continues to collaborate with researchers and visitors, always sharing his in-depth knowledge of the region. "The idea of honoring Alair arose to strengthen this bond between the local community and the region's fauna," says the researcher. "I hope that the little frog, which is only known in the park, can become a symbol of pride and conservation for the residents."

With altitudes ranging from approximately 1,000 to over 2,000 meters, Forno Grande State Park is home to a wide variety of microenvironments and plant formations, which favors the occurrence of rare and endemic species. "The presence of these species ensures a healthier ecosystem, which is directly related to our well-being. I think it's essential that the local population feels proud to live near such a special environment," adds Santos.

The full article can be accessed at: https://onlinelibrary.wiley.com/doi/10.1111/zsc.70001