A team led by researchers from the University of Delhi has discovered seven new species of night frogs in India's Western Ghats mountain range.
The new species, described in a paper published in the journal PeerJ, raises the total number of known night frog species to 35. Night frogs, or frogs belonging to Nyctibatrachus genus, are considered to be one of the smallest animals in the world, making their discovery very crucial.
"It was extremely difficult to locate the calling individuals because they were always hiding under thick ground vegetation and leaf litter," said Sonali Garg, a Ph.D. student at the University of Delhi and co-author of the study, in a report from National Geographic. "If we went too close, they would stop calling, making it even more difficult."
For the study, the researchers embarked on a five-year survey in the forests of Kerala and Tamil Nadu. The researchers collected specimens of the night frogs and analyzed it in a laboratory. The frogs' DNA, physical characteristics and calls confirmed that they belong to new species.
Among the seven new species, four were about the same size of an M&M and can perfectly fit in the thumb. The smallest of the newly discovered species measure between 0.5 and 0.6 inches. They are the Nyctibatrachus manalari, N. pulivijayani, N. robinmoorei and N. sabarimalai.
The largest of the newly described species is the N. radcliffei, which measured 1.5 inches. The N. racliffei is followed by N. webilla and N. athirappillyensis at 0.7 inches and 0.8 inches, respectively.
Despite being classified as a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site and having one of the richest biodiversity hotspots in the world, large plantations and human settlements are being built in the Western Ghats.
Due to this, most of the habitats of the night frogs are prone to disturbance caused by human activities. Most of the seven newly discovered night frog species were found outside the protected areas and near human settlements, with five of them already facing anthropogenic threats requiring immediate conservation prioritization.
Aside from human activities, climate change could also affect the frog's overall survival. The researchers noted that the warming climate is forcing the frogs to move their ranges up in elevation. The researchers still don't know how the changes in elevation could influence the frog's life. However, they are concern how a small change could wipe out their entire population from an area.