The Peruvian Parque Nacional del Manu, a protected area in the southeastern Amazon region of the country, has been proven to be home to the largest amphibian (and reptilian) diversity on earth. This is the outcome of a survey from scientists of several American universities who set out to record those specific taxons in this protected area. Previously, the Yasuni National Park in Ecuador (topic of study in an earlier blogpost) held this record with a total of 150 amphibian species, but ‘Manu’ exceeds this number with a staggering total of 155 amphibian species (and 132 reptilian species). Both protected areas lie within the region of the Tropical Andes which is known as thé biodiversity hotspot for amphibians. The Tropical Andes extends from the snow-capped peaks of the Andes and the Andean grasslands, through the montane cloud forests into the lowland rainforests of the Amazon. While Yasuni National Park only protects Amazon lowland rainforest, in Parque Nacional del Manu all these ecosystems are found within its boundaries and the high diversity in landscapes and habitats is reflected in the spectacular biodiversity. The diversity of birds and butterflies in the park is unrivaled in the world as well.
The research, published in the journal Biota Neotropica, was conducted by Alessandro Catenazzi of the Southern Illinois University Carbondale, Edgar Lehr of Illinois Wesleyan University, and Rudolf von May of the Museum of Vertebrate Zoology at University of California, Berkeley. These scientists have been working in ‘Manu’ for a long time, starting in the nineties of the previous century, and decided to record all amphibian and reptilian species in the park, because such an inventory had not been done before and they see it as a crucial first step towards conservation of the species. Von May explains to National Geographic that his research focus is on explaining how species’ habitat use and elevation relate to their physiology and evolutionary history. For example, frog species living at a high elevation seem to be more tolerant to fluctuations in temperature than their lower-living counterparts. In light of our changing climate this is something to investigate further. Catenazzi has published interesting work on chytridiomycosis in Parque Nacional del Manu and I would like to discuss this briefly.
In 1999 and about ten years later, in 2008 and 2009, Catenazzi and colleagues surveyed the Upper part of ‘Manu’ focusing on anurans living at an elevation of 1200-3700 meters. They found that in 2008 and 2009 less species were present and mostly in lower densities than ten years before. Especially the arboreal and stream-dwelling frogs seemed to be hit hard with a 55% reduction in species number, but the terrestrial anurans were affected negatively as well. Although no explanation can be given with certainty for the dwindling numbers, the fungus Batrachochytrium dendrobatidis, causing chytridiomycosis, appears to be the culprit. The timing of the arrival of the fungus, between 1999 and 2008, seems to be consistent with other studies that predicted a southward movement of the fungus from Ecuador to Peru. Although there is still considerable uncertainty surrounding this southward movement and whether the fungus is the main responsible driver, the scientists did prove that chytridiomycosis is causing anuran deaths in this park and that the disease is present in live individuals of species that can cope better with it, and in this way might act as reservoirs for the disease. Considering the history of chytridiomycosis throughout the world, the presence of the disease is bad news for amphibians residing here.
So even though the area is well protected and habitat loss is no important driver for species loss here, still the amphibians of ‘Manu’ are under considerable threat. This can be seen as a global threat, because of the immense importance of the area for amphibian biodiversity: the park only covers 0.01% of the planet’s land area, but no less than 2.2% of all known amphibians are found here. Clearly, it is important to further study the animals here and take appropriate conservation measures. As the researchers say: “”The sudden disappearance of a sizable proportion of the montane anuran fauna despite the excellent state of conservation of the forest and protection granted by Manu NP shows that additional conservation actions are needed to preserve amphibian biodiversity.” I can tell from my own experience, as I had the privilege to visit the park, that conserving ‘Manu’ and its species would be a great win for humankind.
For more information and pictures I refer you to Mongabay