Some of the smallest known frogs were recently discovered following a five-year survey in India. Seven new species of “night frogs,” in the Nyctibatrachus genus, include four species that are among the tiniest frogs ever found, capable of comfortably crouching on a thumbnail with room to spare.

Though the frogs were abundant in the survey area, their minuscule size and chirping calls -- which resemble the sounds of insects -- enabled them to remain undetected until now, scientists wrote in a new study.

Their discovery raises the total number of known night frog species to 35, with seven species recognized as miniaturized — smaller than 0.7 inches. [So Tiny! Miniature Frog Species Are Among World’s Smallest (Photos)]

The smallest of the newly described frogs -- Nyctibatrachus manalari, N. pulivijayani, N. robinmoorei and N. sabarimalai -- measure between 0.5 and 0.6 inches.

N. webilla and N. athirappillyensis are slightly larger than their cousins at approximately 0.7 inches and 0.8 inches respectively, while the largest of the new finds, N. radcliffei, measured 1.5 inches.

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 sabarimalaiI), 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 5-rupee coin (24 mm diameter)]. SD Biju

Night frogs are native to the Western Ghats mountain range, one of the world’s richest biodiversity hotspots and a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site. The region runs parallel to India’s western coast, covering an area measuring approximately 54,054 square miles.

It is home to hundreds of species of animals and plants that are recognized as globally threatened, with 145 species listed as endangered and 51 as critically endangered, UNESCO reported in a site description.

Over the past decade, scientists have described 103 new species from the Western Ghats, including the unusual Indian purple frog, which is found nowhere else on Earth and is the only living frog in an evolutionary lineage dating back to the Jurassic.

What the future holds for night frogs -- and for many of their fellow amphibians -- is uncertain, as more than 32 percent of the Western Ghats frogs are threatened with extinction, according to the study co-author, SD Biju, a biologist and head of the Systematics Lab with the Department of Environmental Studies at the University of Delhi, India.

“Out of the seven new species, five are facing considerable anthropogenic threats and require immediate conservation prioritization,” Biju said.

The new findings emphasize that biodiversity in the Western Ghats is dramatically underestimated -- even in well-studied groups like night frogs -- and highlight the urgency of implementing conservation measures to protect threatened wildlife, and to preserve the habitats of as-yet undiscovered species, the study authors wrote.

The findings were published online Feb. 21 in the open access journal PeerJ.

Original article on Live Science.

Editor’s Recommendations</s>Behold: 4 New Species Of Tiny Frogs Smaller Than A Fingernail

Four newly discovered frog species are so tiny that they can sit comfortably on a fingernail, making them some of the smallest-known frogs in the world.

Scientists said in a video that they were "surprised to find that the miniature forms are in fact locally abundant and fairly common." The frogs likely escaped notice until now because of their tiny size and secretive habitats, hidden under damp soil or dense vegetation.

The team from the University of Delhi also found three other, larger species from the same genus of night frog, Nyctibatrachus, in a study published in PeerJ.

The largest of the seven frog species, Radcliffe's Night Frog, comes in at about 38 mm, while the smallest, Robin Moore's Night Frog, is some 12.4 mm. Take a look at how they measure up:

The researchers proved these are new species "by using an integrated taxonomic approach that included DNA studies, detailed morphological comparisons and bioacoustics."

These frogs are also distinctive because of their insect-like calls, which sound a little like a cricket chirping — yet another reason why they might have been previously overlooked.

Researcher Sonali Garg, who is a doctoral student at the University of Delhi, explained in an interview with PeerJ how these miniature frogs differ from other night frogs:

Taken together, the seven new species found in the Western Ghats Biodiversity Hotspot suggests that more species are likely to be found in the area. "The past decade has witnessed an exponential increase in the number of new amphibian species described from this region," the researchers say. Some 159 new species were identified in the area between 2006-2015.

Night frogs are an "ancient group of frogs that diversified approximately 70-80 million years ago," Garg said. The team's findings mean a far higher number of the night frog genus are miniature than previously known.

"Previously, the Night Frog genus comprised of 28 recognized species of which only three were miniature sized," the researchers stated. "Now the total number of known Nyctibatrachus species has increased to 35, of which 20 percent are diminutive in size."

The newly discovered frogs all reside in small areas in the southern Western Ghats states of Kerala and Tamilnadu, Garg said. That may not bode well for them — the researchers say some of the habitats are in areas that are not protected.

"Out of the seven new species, five are facing considerable anthropogenic threats and require immediate conservation prioritization," said University of Delhi's SD Biju.</s>Scientists have discovered new frogs so tiny they can sit on a thumbnail.The seven new frogs were discovered in the forests of the western coast of India.They live on the forest floor and make insect-like calls at night. Scientists say there are a lot of these new frogs, and that they were likely overlooked because they are so small, their habitats are hard to find, and they don't make typical frog sounds.</s>Indian researchers have discovered seven new frog species in the mountainous region of Western Ghats. The newfound frogs also include four tiny species that range between 12.2-15.4 mm. These miniature frogs are so small they can comfortably sit on a coil or thumbnail.

All of the newly discovered frog species belong to genus Nyctibatrachus, commonly known as Night Frogs, which is a group endemic to Southwestern India. The species from this genus are known to occur in five southern stretching from the southern tip of Indian Peninsula in Tamil to northern Maharashtra. The latest find is a result of five years of extensive explorations in India's leading biodiversity spot Western Ghats.

New miniature frog species were spotted on the leaf litter of a damp forest. This is unusual for genus Nyctibatrachus as most of their species are found in the streams. Researchers were also surprised to see the abundance of these frogs in their respective localities. These frog have probably not been spotted before because of their small size and almost hidden habitats.

“The miniature ones were the big surprise. It was believed miniature frogs less than 15mm were exceptions - we've found four.” Coresearcher Sonali Garg from University of Delhi told The Telegraph India.

Evidence from multiple sources has confirmed that these species have not been seen or reported by science before. The Night Frog genus was previously known for 28 recognized species of which only three were less than 18 mm. Now the total number of known species in the genus has increased to 35. However, the future is looking very grim for all these new amphibians. Each of these described species is currently known only from single localities in the southern Western Ghats and some are even outside protected areas.

Prof SD Biju, who led the new study and has also described more than 80 new species of amphibians from India, says."Over 32 percent, that is one-third of the Western Ghats frogs are already threatened with extinction. Out of the seven new species, five are facing considerable anthropogenic threats and require immediate conservation prioritization.”</s>After five years of extensive explorations in the Western Ghats in India, researchers have discovered seven new frog species, known as Night Frogs.

The adorable creatures are among the smallest in the world, and four of the new species are tiny enough to fit on a fingernail.

Despite only just being discovered, the researchers warn that five of the new species are under direct threat of extinction, and urge environmentalists to set up conservation programmes immediately.

Researchers from the University of Delhi discovered the frogs in the Western Ghats, which is known to be a hotspot for biodiversity in India.

Unlike other frogs in the genus that live in streams, the new miniature frogs were found under damp leaves and vegetation.

The researchers were surprised by the relative abundance of these previously unknown species at their collection localities.

Sonali Garg, who worked on the study, said: 'The miniature species are locally abundant and fairly common but they have probably been overlooked because of their extremely small size, secretive habitats and insect-like calls.'

In the lab, the frogs were confirmed as new species using DNA studies and detailed analysis of sounds the animals produce.

Until now, 28 species of Night frogs were known, but the new finding takes the total to 35 species.

The discovery of the new species can provide useful insights into the evolution of frogs in the Western Ghats.

The past decade has seen a huge increase in the number of new amphibian species described from this region.

Of the 1,581 new species of amphibians found globally in 2006-2015, the highest number were from the Brazilian Atlantic Forest, followed by the Western Ghats-Sri Lanka biodiversity hotspot, with 103 species described alone from the Western Ghats region.

But the researchers warn that the future of many of the new species may be bleak.

Professor SD Biju, who led the study, said: 'Over 32 per cent, that is one-third of the Western Ghats frogs are already threatened with extinction.

'Out of the seven new species, five are facing considerable anthropogenic threats and require immediate conservation prioritisation.'</s>Scientists from India have discovered seven new frog species belonging to the genus Nyctibatrachus, commonly known as Night Frogs. This find is a result of five years of extensive explorations in the Western Ghats global biodiversity hotspot in India. Four out of seven of the new species are miniature-sized frogs (12.2-15.4 mm), which can comfortably sit on a coin or a thumbnail. These are among the smallest known frogs in the world.

Unlike other frogs in the genus that are predominantly stream dwelling, the new miniature frogs were found under damp forest leaf litter or marsh vegetation. Scientists were surprised by the relative abundance of these previously unknown species at their collection localities. "In fact, the miniature species are locally abundant and fairly common but they have probably been overlooked because of their extremely small size, secretive habitats and insect-like calls", says Sonali Garg who undertook this study as part of her PhD research at University of Delhi.

In the lab, the newly sampled frogs were confirmed as new species by using an integrated taxonomic approach that included DNA studies, detailed morphological comparisons and bioacoustics. Evidence from these multiple sources confirmed that the diversity of Night frogs is higher than previously known and particularly remarkably for the miniaturized forms. Previously, the Night Frog genus comprised of 28 recognized species of which only three were miniature-sized (<18 mm). Now the total number of known Nyctibatrachus species has increased to 35, of which 20 percent are diminutive in size. This frog genus is endemic to the Western Ghats of India and represents an ancient group of frogs that diversified on the Indian landmass approximately 70-80 million years ago.

The discovery of several new species of ancient origin can provide useful insights into the evolution of endemic frog lineages in the Western Ghats, which is a leading amphibian hotspot. The past decade has witnessed an exponential increase in the number of new amphibian species described from this region. Of the total new species of amphibians (1581) described globally between the years 2006-2015, the highest number were from the Brazilian Atlantic Forest (approximately 182) followed by the Western Ghats-Sri Lanka biodiversity hotspot (approximately 159), with 103 species described alone from the Western Ghats region.

However, the future of many of the new species may be bleak. All the newly described species are currently known only from single localities in the southern Western Ghats, and some lie outside Protected areas. Researchers found the Radcliffe's Night frog and the Kadalar Night Frog inside private or state-owned plantation areas facing threats such as habitat disturbance, modification and fragmentation. The Athirappilly Night Frog was found in close vicinity to the Athirappilly waterfalls and the Sabarimala Night Frog near the Sabarimala pilgrimage centre, both of which are disturbed by anthropogenic activities. "Over 32 percent, that is one-third of the Western Ghats frogs are already threatened with extinction. Out of the seven new species, five are facing considerable anthropogenic threats and require immediate conservation prioritization", says Prof SD Biju, who led the new study and has also formally described over 80 new species of amphibians from India.

Explore further: Discovery of a new mating position in frogs

More information: "Seven new species of Night Frogs (Anura, Nyctibatrachidae) from the Western Ghats Biodiversity Hotspot of India, with remarkably high diversity of diminutive forms", DOI: 10.7717/peerj.3007</s>Scientists in India have made a sweet discovery: Seven new frog species, four of which are about the size of an M&M https://t.co/AyyyJZK2Fg

Scientists believe that these miniature frogs were overlooked because of their insect-like calls and secretive habitats. The new frog species belong to the genus Nyctibatrachus, commonly known as Night Frogs. This find is a result of five years of extensive explorations in the Western Ghats by a group of biologists led by Prof SD Biju of University of Delhi.

​Unlike other frogs in the genus that are predominantly stream dwelling, the new miniature frogs were found under damp forest leaf litter or marsh vegetation. Scientists were surprised by the relative abundance of these previously unknown species at their collection localities. The Night Frog genus composed of 28 recognized species of which only three were miniature-sized (<18 mm). Now the total number of known night frog species has increased to 35, of which 20 percent are diminutive in size.

This frog genus is endemic to the Western Ghats of India and represents an ancient group of frogs that diversified on the Indian landmass approximately 70-80 million years ago, according to the study published in the Science Daily.

The future of these night frogs is uncertain, as more than 32 percent of the Western Ghats frogs are threatened with extinction.

“Over 92% of the presently known 225 amphibian species of the Western Ghats are endemic to this region. An exponential two-fold increase in the number of species over the last decade and a half has evidenced that a vast majority of amphibians of this region had remained undiscovered until recently and the trends also suggest that the actual diversity may still be higher than currently estimated. The present rate of species description from the Western Ghats is also comparable to the eight ‘hottest’ biodiversity hotspots of the world,” reads a study published in science journal PeerJ.

Western Ghats mountain range is one of the world’s richest biodiversity hotspots and a UNESCO World Heritage Site. The region runs parallel to India’s western coast, covering an area measuring approximately 54,054 square miles.

It is home to hundreds of species of animals and plants, of which 145 species listed as endangered and 51 as critically endangered, according to the UNESCO.

Never miss a story again — sign up to our Telegram channel and we'll keep you up to speed!</s>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.</s>The latest discoveries in the amphibian world are tinier than the average fingernail.

After six years of trudging through the rainforests of the Western Ghats in southern India, scientists have discovered seven new endemic species of Nyctibatrachus, or night frogs. Four of these species are hardly 14 mm in length. The study outlining this discovery was published on Tuesday.

The insect-like calls of the newly-discovered night frogs species deceived scientists on several occasions.

“For a long time, we heard these calls while we were walking through certain forest patches and thought they were insects till we spotted them under leaf litter,” said Sonali Garg, who undertook the study as part of her doctoral research at the University of Delhi. These miniature species were locally abundant, she said, but they had probably been overlooked by previous researchers because of their extremely small size and secretive habitats, apart from their deceptive insect-like calls.

According to the study, night frogs represent an ancient group of frogs that spread across the Indian landmass approximately 70 million to 80 million years ago. The first species belonging to this group was documented in 1882, and since then the group has been relatively well-studied.

These seven species add to existing knowledge about 28 species that have been identified so far as belonging to the ancient lineage of night frogs. This frog genus is endemic to the Western Ghats and is found near the marshy forests and mountain streams of five states – extending from the southern tip of Tamil Nadu across the tropical landscape of Kerala, Karnataka and Goa till northern Maharashtra.

“These frogs are very important links to understand how evolution took place over time,” said Garg. “In terms of evolutionary studies, these are the remaining relics of ancient frogs that lived on this landscape.”

Of the 28 species of night frogs, 13 species were identified and documented over the last five years. With every discovery, scientists have realised just how diverse the group was. In 2007, Garg’s mentor SD Biju, who has discovered over 80 species of frogs so far, found India’s smallest frog species Nyctibatrachus minimus, that is just 10 mm in length. Popularly known as the frogman, Biju and his team went on to find 12 other species belong to the night frogs group in 2011. The largest species of night frog found, Nyctibatrachus grandis, is 77 mm in length and lets out a deep croaky call.

Not only do night frogs show immense diversity in terms of size and calls, but also in reproductive behaviour. Across the 7,500 species of frogs found across the world, researchers have observed six mating positions. But in 2011, a study also found a species of night frog, known as the Bombay night frog, which practices a seventh mating position – the dorsal straddle – a technique which is not found in any other frog species till date.

“This is a very interesting group of organisms to study since it is so diverse in every way,” said Garg. “Its DNA gives us information of a much longer time frame. It is evolutionarily significant information if we want to understand why certain frogs are found in small regions, or distributed widely, or to explain their diversity.”

Of the 35 night frogs found in the Western Ghats so far, seven are miniature, less than 18 mm in length.

“In group after group of amphibians, miniatures have evolved,” said David B Wake, an evolutionary biologist at the University of California, Berkeley, who has studied miniaturisation in amphibians over many years. “We have been slow to understand this because the miniatures often look like juveniles of common larger forms and have been overlooked.”

Wake explained that miniaturised species often occur in environments that are not usually the favoured habitat of larger frogs. For instance, in the case of the new species found by Garg, the miniature frogs are more terrestrial and occur in leaf litter unlike the larger ones that are found largely near streams.

“Also, in salamanders and in groups of frogs in many parts of the world, the miniatures have abandoned the tadpole stage,” said Wake. “Eggs develop directly into miniatures of the adults and the eggs are laid on land. This frees them from reliance on water and expands ecological and evolutionary opportunities.”

The miniature frogs found by the team, however, are known to go through the tadpole stage. But the team has observed certain other adaptive changes across the new species. While the larger frogs by the streams had webbed feet used for swimming and sticking onto slippery surfaces, this was not found in miniature frogs.

“There was little webbing of the feet in the miniature frogs, probably because they did not need life in water,” said Garg. “This indicates that they are adapting to a terrestrial habitat.”

Although night frogs are quite common across the Western Ghats, they face considerable threats from human activity.

“While new species are being identified, the known ones are moving towards extinction,” said Biju. He said that frogs are already threatened with extinction in one-third of the Western Ghats. He said of the seven new species found, five required immediate priority for conservation since they were all found outside the protected forest zone.

One of the new species – the Athirappilly night frog – was discovered close to Kerala’s Athirappilly falls, where a mega hydroelectric project is proposed to be set up.

Another species, which Biju and Garg have named the Sabarimala night frog was found in the vicinity of the Sabarimala temple, a pilgrim site located inside the Periyar Tiger Reserve in Kerala. “These species were purposely named after their collection localities in order to highlight the threats they might be facing due to anthropogenic disturbance,” said Biju.</s>New species of tiny frogs that can fit comfortably on a coin have been discovered in India.

Seven new species of frog — some of the smallest in the world — were found after five years of searching in the Western Ghats, a mountain range in Southwestern India known to be a biodiversity hotspot.

They might have just been discovered but their future is already in doubt, according to Professor SD Biju from the University of Delhi, who led the study.

“Out of the seven new species, five are facing considerable anthropogenic threats and require immediate conservation prioritization,” he said in a statement.

Belonging to the night frog genus, four of the new species are just 12.2 to 15.4 millimeters long.

They bring the number of species in the genus to 35, and reveal greater diversity than previously thought. Some night frogs can be up to 10 times bigger than their minute cousins.

While their larger cousins prefer rapid streams, the new species were found under marsh vegetation and damp forest leaf litter. Unlike their more aquatic peers, they do not have webbed feet.

“The miniature species are locally abundant and fairly common but they have probably been overlooked because of their extremely small size, secretive habitats and insect-like calls,” said Sonali Garg, who undertook the study as part of her PHD research.

Night frogs are native to the Western Ghats region and belong to an ancient frog group that dates back 70 to 80 million years.

SD Biju from University of Delhi said that the discovery of the new species revealed insights into their evolution and preferred habitats.

“These smaller species occupy smaller niches, call like insects and lay fewer eggs [than their larger peers]” he told CNN.

Among the evolutionary advantages of miniaturization in animals were opportunities to occupy new habitats and exploit alternate food sources, he said.

Over 1,581 new species of amphibians have been discovered worldwide in the last decade, with the highest number coming from the Brazilian Atlantic Forest, followed by the Western Ghats region.

But humanity’s new found appreciation for the diversity of these species might be short lived, with many facing extinction.

“Over 32%, that is one-third of the Western Ghats frogs, are already threatened with extinction,” he said.
Several new species of tiny frogs are discovered in India.