The race is on to research Colombia’s upland amphibians
Increased scientific investigation of frogs and salamanders in the páramo ecosystems of Colombia is vital for safeguarding the abundance of endemic amphibians in the country. This is according to a systematic study in Tropical Conservation Science recently published.
The survey revealed gaps in scientific knowledge about scores of endemic amphibians in the threatened ecosystem which the authors warn are a barrier to the development of conservation legislation, to securing funding for conservation efforts and to efficient and effective implementation of conservation programs.
Understanding the population changes, vulnerability to disease, climactic adaptations and community ecology of amphibian species is crucial to securing legislation and funding for conservation, as well as knowing how to use these resources once you have them. New species of amphibians are being discovered all the time, so the race is on to identify, understand and protect species before they are lost forever.
Mass amphibian extinction?
You may have heard that the mountain chicken frog (leptodactyllus fallax) of Dominica and Montserrat has been almost entirely wiped out. On a recent count, only 21 of these 21cm-long frogs were found in the wild on Dominica and few more on Montserrat. The blame for this disaster is shared between the chytrid fungal infection, habitat loss to human development and storm damage from Hurricane Maria. Leptodactyllus fallax seems to be on track for what has been called the fastest extinction of modern times.
There is hope that some members of this prodigious species that have developed resistance to the chytrid fungus will survive on Dominica.
This is concerning news for the inhabitants of the aforementioned Caribbean islands, who used to enjoy roasting this once-abundant anuran, and the exact same perils confront many of the world’s 7,556 known extant frog species (and the unknown species too). A major outbreak of chytridiomycosis, beginning in Central America in the 1980s is linked to the decline of over 200 species of frogs worldwide, including the likely extinction in Colombia of the páramo-dwelling leopard rocket frog (aromobates leopardalis). The greatest loss of species has occurred in Australasia and the Indian sub-continent, but the deadly infection continues to spread on all continents. There is particular concern in the herpetological community for the vulnerable salamanders of North America.
While some frog species have been seen to develop resistance to the disease, global populations face habitat loss and the developing threat of global warming and associated climactic changes. Scientific journal Nature estimates that 40% of the world’s frog species are at risk of extinction as a result of climate change impacts. Amphibians are particularly vulnerable to climate change because their water permeable skin makes them very sensitive to air moisture content. Many species are highly adapted to specific environments and their reliance on transient water sources to reproduce is also a risk factor.
Despite all the bad news, there is cause for hope. Hundreds of other species’ populations have improved as a result of habitat protection schemes, and it is the need to promote, legislate, fund and effectively implement such schemes in Colombia’s páramo ecosystem that impels this new research.
The leopard rocket frog (aromobates leopardalis) of the Sierra Nevada de Santa Marta páramo has not been seen in over a decade.
What is the páramo landscape?
If you haven’t heard of them before, páramos are misty moorlands between three and five thousand metres up in the Central and South American High Andes – above the timber line, below the snow line.
I had the chance to visit the páramo in Tolima earlier this year. It is a quiet, wet, huge and frankly quite scary place. A gloomy expanse of rolling rocks and strange grasses wreathed in cloud. Out of the mist, looms a forest of giant shrubs, a turkey vulture wheels overhead.
For a moment, the mist clears and reveals an impossibly far below, then an impossibly far above.
Between your feet, flowering mosses from another planet. Thin air. The sound of the hummingbird’s wings reaches you after it has disappeared. From somewhere, a trickling. The damp cold creeps in at your neck. At night it will be much, much colder. You don’t see the Andean condor, the spectacled bear or the Andean wolf, but you know that they too are somewhere in this fastness in the clouds.
The biome that has developed in this wild and unsettling place is unique on our planet for its richness and number of endemic species. Just as in the Galapagos Islands, extreme conditions and geographical isolation in the páramo triggers unusually high diversification of species. The result is an abundance of flowering plants, insects and vertebrates that are highly adapted to this valley or that mound and which reside nowhere else on the planet.
As well as giving cover to curious bears, Espeletia capture vapour from passing clouds in their spongy trunks releasing it through the roots into the soil.
Why are Colombia’s páramos so important to frogs and what threats do they face?
Frogs and salamanders have adapted and diversified to withstand the high exposure to wind and UV and sudden changes in temperature which characterise the páramo climate. They have become the most diverse vertebrate lineage in the páramo. The páramo biome is found in Costa Rica, Venezuela, Colombia, Ecuador and Peru, but Colombia has the greatest share of páramos and the greatest number of amphibian species in this ecosystem. Science knows of 134 frog species native to the Colombian páramos (as well as a smattering of salamanders). By this count, Colombia’s páramos sustain over 2% of the world’s known frog species. 95 of these species are endemic to Colombia.
The Andes is experiencing accelerated ecosystem loss as a result of mining, agriculture and climate change. Less than 60% of Colombia’s páramos are within the national system of protected areas. The agricultural frontier is expanding into Colombia’s páramos with the land use in some of these areas changing by over 18% in recent years. Changes to the “natural cover” can lead to the frogs’ habitats changing and to population decline and increased likelihood of extinction. The authors calculate that about two thirds of páramo amphibians are either vulnerable, endangered or critically endangered. These species will decline and may be lost if their habitats are not protected from agricultural expansion and mining activities.
Worryingly, the authors describe “a clear lack of efforts to mitigate threats to the habitat of these species or to implement concrete actions for their conservation. (i.e., amphibian translocation, citizen science, engagement of landowners and other volunteers in managing land for amphibians, or management plans with the support of environmental institutions.” They believe a lack of research could be at the root of this problem.
The most researched frog in the Colombian páramo is the green spotted treefrog (dendropsophus molitor)
What did they find?
There has been a huge increase in research on amphibians in the páramos of Colombia since the turn of the millennium, but more needs to be done.
Accurate data from the field, including the size, location and change over time of populations is the bread and butter of conservation work. Yet, they found a startling lack of reliable data about population dynamics which makes it hard for scientists to assess the risks of species loss or to implement effective conservation measures. Amazingly, for more than 80% of páramo amphibians in Colombia little or nothing is known about their “ecological requirements,” i.e. the exact conditions that they need to survive.
Perhaps unsurprisingly for a country still struggling to bring to a close decades of armed conflict, some areas of the country have been understudied, particularly in the Eastern cordillera and in the north of the country. Of the thirty-six páramo complexes, there is no published scientific research on amphibians for six páramo complexes. Thus, there are likely many undescribed or unidentified species at large in the páramos. This research tells us that the race is on, not just to find and identify these populations, but also to understand the changes and risks that they face.
A yellow bulldozer flattens a new stretch of road that is being laid through this once-pristine landscape.
Referenced works:
Luedtke, J. A. et al. (2023). Ongoing declines for the world’s amphibians in the face of emerging threats. Nature.
Saboyá Acosta, L. P. & Urbina-Cardona, J. N. (2023). Current State of Knowledge of Páramo Amphibians in Colombia: Spatio Temporal Trends and Information Gaps to Be Strengthened for Effective Conservation. Tropical Conservation Science.
