As for why they evolved to be so small, Garg explained that "miniaturization can provide various evolutionary advantages, such as opportunities to occupy new environments and habitats and to exploit alternate food sources. Miniature forms physically also require smaller niches compared to larger forms, and their sizes can be helpful in avoiding predators."
"Smaller forms can reach reproductive maturity at an earlier age, which can also be an important advantage for any species to successfully propagate," she said.
Biju said all the frogs are "friends of farmers," because the frogs eat millions of insects that damage to crops. The new frogs may also hold medical potential since research on other frogs has led to medical advancements. For example, frog skin-derived compounds known as alkaloids are being investigated as a substitute for morphine. In terms of ecosystem benefits, frogs not only help to keep insect numbers in check, but they also serve as food for birds, snakes and other animals.
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The Western Ghats, plus nearby territory in Sri Lanka, is proving to be a frog and other amphibian hotspot - 159 new amphibian species were found there from 2006–2015. Only the Brazilian Atlantic Forest area tops the Western Ghats-Sri Lanka region for more amphibian discoveries over the same period (182).
Larger mammals in these areas often receive star conservation status, but Biju said it's important to not forget the small inhabitants of these biodiversity hotspots.
"In the forests, many frogs live along with many large and charismatic animals, and can be protected by conservation measures that aim to protect those areas in general," he said. "However, habitat destruction and fragmentation can have larger impacts on smaller animals like frogs, because they occupy small ranges. Any small alterations can sometimes wipe out their entire population from an area."
Middle photo: Seven new species discovered from the Western Ghats. A. Radcliffe's Night Frog (Nyctibatrachus radcliffei), B. Athirappilly Night Frog (Nyctibatrachus athirappillyensis), C. Kadalar Night Frog (Nyctibatrachus webilla), D. Sabarimala Night Frog (Nyctibatrachus sabarimalai), E. Vijayan's Night Frog (Nyctibatrachus pulivijayani), F. Manalar Night Frog (Nyctibatrachus manalari), G. Robin Moore's Night Frog (Nyctibatrachus robinmoorei). [(D–G. Size of the miniature species in comparison to the Indian five-rupee coin (just under an inch in diameter)]. Credit: SD Biju