Revision as of 13:02, 16 July 2017

Burrowing frogs from the Western Ghats

Sonam Joshi 
The Discovery Of Four New Frog Species Confirms Western Ghats Region As A Global Biodiversity Hotspot, June 20, 2017: The Huffington Post

One of the 4 species of burrowing frogs, Courtesy: S D Biju, Sonam Joshi 
The Discovery Of Four New Frog Species Confirms Western Ghats Region As A Global Biodiversity Hotspot, June 20, 2017: The Huffington Post

One of the species of burrowing frogs, Courtesy: S D Biju, Sonam Joshi 
The Discovery Of Four New Frog Species Confirms Western Ghats Region As A Global Biodiversity Hotspot, June 20, 2017: The Huffington Post

One of the 4 species of burrowing frogs, Courtesy: S D Biju, Sonam Joshi 
The Discovery Of Four New Frog Species Confirms Western Ghats Region As A Global Biodiversity Hotspot, June 20, 2017: The Huffington Post

Delhi University researchers discover four new burrowing frogs in the Western Ghats.

A PhD student from Delhi University has discovered four new species of burrowing frogs in the Western Ghats, further cementing the region's place as a global biodiversity hotspot with an unprecedented rate of new frog discoveries in the last decade.

The findings are the result of five years of extensive research by Delhi University student Sonali Garg, and her supervisor Professor SD Biju, who is also known as the 'Frog Man Of India'. The species belong to the Indian frog genus Fejerarya, but are unique because of their ability to burrow using their hind legs.

Discovered in Kerala and Maharashtra, the frogs were confirmed as new species by using an integrated taxonomic approach that included DNA studies, detailed morphological comparisons and bio-acoustics. They include the Maohrahan's Burrowing Frog discovered in the Agasthyamala Hills in south Kerala, the Kadar Burrowing Frog, discovered in the Vazhachal forest in Kerala, the CEPF Burrowing Frog found in Amboli in Maharashtra, and the Neil's Cox Burrowing Frog found in the Parambikulam tiger reserve in Kerala.

"Burrowing frogs are very rare, cryptic and difficult to find. Only 7-8 out of the 230 frog species in the Western Ghats are burrowing frogs," Biju told HuffPost India. "While most frogs in the Western Ghats can be easily spotted during the monsoon, these frogs can be seen for only two to three weeks in June and July. Otherwise, they stay hidden underground or under wooden logs." This also makes these frogs the most susceptible to weather patterns. Since they only breed for a very short period of time, any changes in weather patterns can affect their numbers.

"Our study highlights a fairly common group of frogs that is usually found closer to human habitations but is still not documented properly. More extensive studies are required to scientifically identify and describe the Western Ghats frogs which are already facing extinction threats from various human activities," Garg, who conducted this study as part of her PhD research at Delhi University, said.

In February, Garg and Biju had announced the discovery of four news species of the world's smallest frogs in the Western Ghats. The frogs were so tiny that they could even sit on a finger nail. There has been an exponential increase in the number of new amphibian species discovered in the Western Ghats in the last decade. Out of the 1581 new species of amphibians discovered between 2006 and 2015, the second-highest number were from the Western Ghats-Sri Lanka biodiversity hotspot, numbering approximately 159. Out of these, 103 were from the Western Ghats alone.

In fact, the number of amphibian species discovered in the Western Ghats habitat has nearly doubled within a short span of ten years. Biju attributes the region's biodiversity to factors such as the Western Ghats being isolated from the mainland, as well as the wide array of habitats found within it.

"If you look at the pattern of discoveries, you can see that only about 30-40% of the flora and fauna, especially lower forms of species, in the Western Ghats has been discovered or documented," Biju said. "I believe that we will have to wait for at least another 10 years to fully understand the diversity of life forms in this region.”

However, about one-third of the frogs in the Western Ghats are already threatened by extinction. "Many of these frogs are extremely rare and found only in specific areas," Biju said. "Any small change in the habitat is more than enough to decrease their population.”

Leaping frogs: Indirana paramakri, Indirana bhadrai

Manash Gohain, Two new species croak at W Ghat, Nov 17 2016 : The Times of India

Leaping frogs: Indirana paramakri (Rocky terrain), Indirana bhadrai (Bhadra)

Two new species of frogs have been discovered by Professor Sathyabhama Das Biju, popularly called India's Frogman. This takes his count to 80 since his first discovery in 2003.The DU scientist's latest find took place in the Western Ghats in Karnataka and Kerala. The species from Kerala has been given the common name of Rocky terrain leaping frog (scientific name: Indirana paramakri), while the one in Karnataka is called Bhadra leaping frog (Indirana bhadrai).

This June, Biju's team chanced upon a strange mating process of the Bombay night frogs, while in 2014 he and his team had discovered seven species in the Western Ghats. In 2012, a team led by him had revealed to the world a new family of legless amphibians known as caecilians. Other successes of the Frogman have come in the forests of Nagaland.

The two frogs species belong to the Ranixalidae family, one of the three ancient frog families that diversified on the Indian landmass long before the extant frogs appeared in this region. “Nearly half of the currently recognised species in this family have been described only in the last three years,“ said Biju, adding that a new genus had been recognised to accommodate three previously known species.

Biju added, “Our surveys in the Western Ghats suggest the further presence of undescribed diversity in this group, thereby increasing all estimates of the family's diversity estimates.“

Biju and doctorate scholar Sonali Garg of the Department of Environmental Studies, DU, conducted extensive sampling of Indirana frogs from across the Western Ghats, and performed DNA barcoding for 200 ranixalid samples.

Nyctibatrachus (night frogs)

Manash Gohain, 4 miniature frogs that can sit on coin or thumbnail, Feb 23 2017: The Times of India

India now has the world's smallest known frogs.Seven such species were discovered by Professor S D Biju, known as the `Frogman of India' for his work on the amphibians, and his team from Delhi University in the Western Ghats. Of the newly discovered species, four are true miniatures with body lengths of 10-15 mm and can comfortably sit on a coin or a thumbnail.

These species belong to the genus Nyctibatrachus, commonly known as night frogs.Evolutionary biologist David Wake of the University of California, Berkeley, expressed surprise because the known nyctibatrachids are relatively larger.

Dr Ariadne Angulo, head of Amphibian Special Group at the International Union for Conservation of Nature, said the immediate priority for these newly described species, after being formally recognised as such, would be to assess their global extinction risk.

Unlike other frogs in the genus that are predominantly stream dwelling, the new miniature frogs were found among damp forest leaf litter or marsh vegetation. “The miniature species are locally abundant and fairly common but they have probably been overlooked all these years because of their extremely small size, secretive habitats and insect-like calls,“ said Sonali Garg, who undertook this study as part of her PhD research at DU.

This discovery of new species of ancient origin can provide useful insights into the evolution of endemic frog lineages in the Western Ghats, which is a global amphibian hotspot.

The past decade has witnessed a big increase in the number of new amphibian species found in this region. Of the 1,581 total new amphibians species reported across the world between 2006 and 2015, around 182 were from the Brazilian Atlantic forest, followed 159 in the Western Ghats-Sri Lanka biodiversity hotspot, with 103 species from the Western Ghats region alone.

Many of these new species are facing threats from human activity. Dr Angulo said that because several of the species have been identified as being range-restricted and impacted by threats, it was important to conduct their extinction assessments. “Once the extinction risk is assessed, both research and conservation actions can be tailored accordingly ,“ she said.

Night frogs, Bombay-

The Times of India, Jun 15 2016

Picture courtesy: The Times of India, Jun 15 2016

Manash Gohain

Discovered: Konkan frog species' touchless sex

The female does much of the courting, the male is furiously possessive of her, but when it comes to intercourse, they make Victorian prudes seem rather forward.Meet the Bombay night frog, an oddity in the anuran world that reproduces without the mates touching each other. The complex world of frogs and toads comprising about 7,000 species has its own little Kama Sutra with six mating positions called amplexus modes (from the Latin word for `embrace') because the male clasps the female about the back during intercourse. But researchers led by Delhi University professor S D Bihu have found that the Bombay night frog adopts a seventh distinct position.

Called dorsal (back) straddle, it has the male spreading itself over the female's back with its feet clutching or resting over leaves and twigs on the sides. Bihu said the male appears to release sperm over the female's back and then moves away . After that, the female lays her eggs, which are fertilised by the sperm trickling down her back. In other frog species, females usually lay eggs during amplexus and males simultaneously release sperms to fertilise them.

“This is a frog with a re markable reproductive behaviour, and this discovery is fundamental to understanding the evolutionary ecology and behaviour in anuran amphibians,“ said Biju.

Bombay night frogs are found mainly near fast-flowing streams in the Western Ghats. They are classified as an ancient group of frogs that diversified 70­80 million years ago. In the breeding season, they can be seen calling from the ground and over hanging vegetation in large numbers, soon after sunset.

The species also shows other rare sexual traits. For instance, the female, as also the male, croaks the mating call during breeding season, a behaviour seen in only 25 species worldwide. Fights between competing males are also common, and last until the intruder is thrown out.

The research team also observed eggs of Bombay night frog being eaten by snakes. It's the first documented observation of snakes eating frog eggs in India.

The research team comprising scientists from University of Delhi, National Centre for Biological Sciences, Bengaluru, and University of Minnesota, USA, observed the frogs in the field for 40 nights during monsoon months between 2010 and 2012. Their findings were published in the journal `PeerJ'

The unique mating position of Bombay night frogs

Ian Sample, Science editor, The Guardian| Froggy style: unique mating position of Bombay night frogs finally revealed, 14 June 2016

The frogs are secretive, breed only at night, and always at the peak of monsoon season, but researchers have finally identified their remarkable mating habits

They mostly come at night. Moments after sunset, and calling as they move, the Bombay night frogs climb high into the trees that overhang rivers swollen by the warm monsoon rains in the forests of Western Ghats in India.

And then the action begins. On rain-soaked leaves, branches and tree trunks, the amphibians pair up. The female sends a willing signal by backing towards her male and touching his head with her toes. What follows is a mating position never seen before in the wild world of frog sex.

The unique mating position of Bombay night frogs: a graphical abstract
Ian Sample, Science editor, The Guardian/ PeerJ

The Bombay Night frogs in Dorsal straddle: a new amplexus mode in frogs. Until Bombay night frogs fell under the spotlight, scientists had identified six mating positions among the world’s 6,650 frog species.

“It’s remarkable,” said Sathyabhama Das Biju, an expert on amphibians at the University of Delhi, who has published a comprehensive report on the frogs’ sexual antics. “So far, this mating position is known only in Bombay night frogs.”

It was 2002 when Biju first witnessed Bombay night frogs mating. But the animals are secretive, they breed only at night, and always at the peak of monsoon season. He got the odd glimpse, but not much else. It took eight more years for Biju to launch a study dedicated to unravelling the beasts’ mysterious breeding habits.

Now, after 40 nights in the forest, Biju has amassed enough field notes, photographs and infrared night-vision video footage from 13 encounters to describe the breeding habits of the frogs, Nyctibatrachus humayuni, in detail.

Until Bombay night frogs fell under the spotlight, scientists had identified six mating positions among the world’s 6,650 frog species. The male might clasp the female around the waist, grab her armpits, hold her head, attach himself to her back with a gluey substance, sit back-to-back, or perhaps sit on her head. But the Bombay frogs do none of these.

Before now, scientists had identified six mating positions among the world’s 6,650 frog species.

Writing in the journal PeerJ, Biju and his colleagues describe how they filmed males clambering on to females. What happened next was unexpected. Instead of clasping his partner, the male took hold of nearby branches or leaves to steady himself. He then appeared to release his semen on to the female’s’ back. Soon afterwards, the female shrugged the male off, and laid her eggs, which, the researchers hypothesise, are “fertilised by semen running down her back and hind legs.”

The researchers discover their remarkable findings.

Asked why the frog might have adopted the unusual approach to mating, Biju said: “We have no idea.” But the new position does have a name: the dorsal straddle. “It differs from the other six positions because the male does not grasp the female under her armpits or head, but instead places his hands on the leaf, branch or tree trunk the pair is sitting on,” he noted.

The 5cm-long Bombay night frog is endemic to the Western Ghats, a mountain range and world heritage site that runs parallel to the west coast of India, spanning a thousand miles from Gujarat to Kerala. While males of all frog species call for mates, Biju’s field recordings reveal that female Bombay night frogs issue their own calls, making them one of only 25 frog species known to do so. He also recorded fights among males, with interlopers forcefully barged out of the way, and predation of the frogs’ fertilised eggs, with 80% of a female’s clutch being eaten by nearby snakes.

Western Ghats, February/ 2017: New night frog species found

T. Nandakumar, Tiny frog species found in Western Ghats, February 21, 2017: The Hindu

A taxonomic approach with DNA studies and morphological comparisons was used to confirm them. ; T. Nandakumar, Tiny frog species found in Western Ghats, February 21, 2017: The Hindu

Five of the seven new ‘Night Frogs’ have small ranges and their habitat is under threat, say scientists

Scientists exploring the forests of the Western Ghats have come across four new species of tiny frogs no bigger than a human thumbnail, which make a distinctive chirping sound comparable to the one of a cricket.

These species are among the seven new ‘Night Frogs’ discovered by a team of researchers from the University of Delhi and the Kerala Forest Department, who spent five years surveying the global biodiversity hotspot.

‘Night Frogs’ belong to the Nyctibatrachus genus endemic to the Western Ghats and represent an ancient group of frogs that diversified on the Indian landmass approximately 70 to 80 million years ago.

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

“The minuscule frogs have probably been overlooked because of their extremely small size, secretive habitats and cricket like calls,” says Sonali Garg, who undertook the study as part of her Ph.D research at the University of Delhi.

The scientists used an integrated taxonomic approach that included DNA studies, detailed morphological comparisons and bioacoustics to confirm the new species. The findings have been published in the latest issue of PeerJ, an open access journal.

Hydroelectric project

While turning the spotlight on the amphibian diversity of the Western Ghats, the discovery also highlights the threat posed by human activities to the species.

The Athirappilly Night Frog was found close to the Athirappilly waterfalls, the proposed site of a hydroelectric project, while the Sabarimala Night Frog was discovered near the hill shrine which receives lakhs of pilgrims every year. The Radcliffe’s Night frog and the Kadalar Night Frog were reported from plantation areas.

“Over 32% of the frog species in the Western Ghats are already threatened with extinction. Out of the seven new species, five face considerable anthropogenic threats and require immediate conservation,” says Professor S.D Biju, who led the study and has formally described over 80 new species of amphibians from India.

Restricted range

“Because several of the new species have been identified as being range restricted and impacted by threats, it is important to assess their extinction risks and tailor conservation strategies for both species and habitats,” said Ariadne Angulo, co-Chair, Amphibian Specialist Group, IUCN, in an emailed response.

The discovery has taken the total number of known Nyctibatrachus species to 35, of which 20% are diminutive in size (less than 18 mm).

As many as 103 new amphibian species have been described from the Western Ghats region between 2006 and 2015.

Tree hole-breeding frogs

Frankixalus, a rhacophorid genus of

The Times of India, Jan 21 2016

Manash Gohain

New frog genus discovered in NE forests 

Professor Sathyabhama Das Biju of DU, popularly known as the `frogman of India', and his team of researchers have discovered a new genus of tree holebreeding frogs in the forests of India's northeast and China. These frogs are special because the tadpoles feed on their mother's eggs.

The team comprised PhD students of Biju and researchers from National Centre for Cell Science (Pune), University of Peradeniya (Sri Lanka), Vrije Universiteit Brussel (Belgium) and American Museum of Natural History (USA).

A tree hole-breeding frog of the genus Frankixalus discovered by Professor Biju; Graphic courtesy: The Times of India, Jan 21 2016

The findings have been published in a paper titled Frankixalus, a new rhacophorid genus of tree hole-bre eding frog with oophagous tadpoles' in the current is sue of international journa PLoS One. The genus has be en named Frankixalus after Professor Franky Bossuyt of Vrije Universiteit Brusse for his contribution to amp hibian research.

“In 1870, British natura list T C Jerdon collected two specimens of a tree frog from forests of Darjeeling and preserved them at Natural History Museum, London. The frog was not found in the wild for over 150 years and was scientifically deemed lost. It remained a mysterious creature--a victim of mistaken identity ever since,“ Biju said.

The overlooked specimens in London were pulled out of the museum cabinets and studied, and the team conducted extensive field work for three years in the forests of Arunachal Pradesh, Manipur, Meghalaya, Naga land, Tripura, Sikkim and Darjeeling (West Bengal).The samples were analysed in the genetics lab of DU.

“Our discovery indicates that documentation of Indian amphibians is still incomplete. Unfortunately , many of them face various extinction threats, especially due to habitat loss and fragmentation. Several populations of the new genus were found in highly disturbed habitats, which is a reason for concern. Taking any conservation effort for amphibians will indirectly conserve several other life forms of that area,“ said Biju.

Biju and his team had in 2014 discovered seven new species of golden-backed frogs from the Western Ghats-Sri Lanka global biodiversity hotspot.