the frogs

meet the frog species that my colleagues and I have discovered and described

Similar Leaf-litter Toad (Leptolalax isos)

Rowley, Stuart, Neang, Hoang, Dau, Nguyen, and Emmett, 2015

Sometimes looks can be deceiving. The Similar Leaf-litter Toad (Leptolalax isos) is nearly identical in appearance to Firth’s Leaf-litter Toad (Leptolalax firthi), and it was only a detailed look at body size, advertisement calls and DNA that revealed that it was a distinct species. First seen in Virachey National Park in Cambodia in 2006, it was only after finding the species again in adjacent Vietnam, and recording its call, that we were able to describe the species as new.

The Similar Leaf-litter Toad is only known from 650–1100 m elevation in northeastern Cambodia and central Vietnam. Habitat within the range of the new species is threatened by deforestation and upstream hydroelectric dams.

Orange-eyed Litter Toad (Leptolalax pyrrhops)

Poyarkov, Rowley, Gogoleva, Vassilieva, Galoyan, & Orlov, 2015

The Orange-eyed Litter Toad was discovered by my Russian colleagues in southern Vietnam and I was invited to be a part of the tricky process of determining if it was indeed a new species. It’s not easy to distinguish species in the genus, so the process involved a lot of detective work, comparing the morphology (colour, pattern and body measurements), DNA and male advertisement call of the new species to all known species in the genus. In the end, we determined that it was indeed a new species, and named it in honour of its beautiful bright orange eyes.

Small and brown with black spots and bright fiery eyes, this tiny forest-dependent species is only known from forests in the western Langbian Plateau, southern Vietnam and is already likely to be under great threat from habitat loss.

Thorny Tree Frog (Gracixalus lumarius)

Rowley, Le, Dau, Hoang, and Cao, 2014

Males of the Thorny Tree Frog sport sharp spines all over their head and back (hence the name!). So why the “thorns”? Well, it seems that only male Thorny Tree Frogs sport spines, and that these become bigger and more impressive in the breeding season. So perhaps the spines help females of the species figure out whether or not a male is ready to breed.

Living on the steep sides of a cold, wet mountain, the Thorny Tree Frog is has another uncommon adaptation. Instead of laying eggs in a stream or pool, it lays its eggs above small, water-filled hollows in trees.

The Thorny Tree Frog is only known from above 1,800 m elevation in the mountains of central Vietnam.

Botsford’s Leaf-litter Toad (Leptolalax botsfordi)

Rowley, Dau, and Nguyen, 2013

With 3.5 m of rain or snow per year, and almost constant fog, conditions near the top of Mount Fansipan, the highest mountain in Indochina, are rather terrible for humans. This may be one reason that this new species, Botsford’s Leaf-litter Frog, was only just discovered. The fact that it took about an hour to track the faint insect-like call of the species down to a tiny brown frog in the mud might be another reason!

So far, Botsford’s Leaf-litter Toad is only known from a small stream near the top of Mount Fansipan, northern Vietnam.

Helen’s Flying Frog (Rhacophorus helenae)

Rowley, Tran, Hoang, and Le, 2012

Armed with large hands and feet that are fully webbed, Helen’s Tree Frog is able glide gracefully down from trees to breed in forest pools, and probably even glide from tree to tree. Because they likely spend most of the time in the forest canopy, they’ve remained largely out of sight, and it wasn’t until recently that it was discovered, less than 100 km from Ho Chi Minh City.

To date, Helen’s Tree Frog is still only known from two patches of lowland forest surrounded by a sea of agricultural land in southern Vietnam. Lowland forests are among the most threatened habitats in the world.

Firth’s Leaf-litter Toad (Leptolalax firthi)

Rowley, Hoang, Dau, Le, and Cao, 2012

It took a long time to figure out this species. In 2007, my colleagues and I found two, strange looking Asian Leaf-litter Toads in the forests of central Vietnam. Both were females, sitting on vegetation in the middle of the forest. In 2009, we found three more of these frogs, sitting in the forest away from the streams, and again, all three were female. We were now well and truly intrigued. Where were all the males? When did this species breed? And was this species truly as rare as it seemed?

In 2010, our questions were answered. As soon as the sun set on our first night back in the forests of central Vietnam a loud chorus of chirping began. It seemed like every couple of metres, a tiny frog was chirping insistently. When we saw the culprit, we knew instantly that it was the elusive males we had been in search of. And there were literally hundreds of them!

Firth’s Leaf-litter toad was described shortly after, and is only known from the mountainous forests of central Vietnam.

Quang’s Tree Frog (Gracixalus quangi)

Rowley, Dau, Cao, and Nguyen, 2011

Quang’s Tree Frog is also known as “the frog that sings like a bird”. Unlike most frog species, that have a repetitive “croak, croak“, Quang’s Tree Frog has what is known as a ‘hyperextended vocal repertoire’. In other words, no two calls of this frog are exactly the same, rather males sing a combination of clicks and whistles that vary in length. The overall result is that males of this species sound remarkably like birds when they call. Listen to the call.

Quang’s Tree Frog is known from the thick, montane forests of northeastern Vietnam.

Misty Moss Frog (Theloderma nebulosum)

Rowley, Le, Hoang, Dau, and Cao, 2011

Only a single adult Misty Moss Frog is known, and this frog was found high in the misty mountains of central Vietnam. Like other Moss Frogs, the Misty Moss Frog is arboreal- living almost entirely in the trees, and even laying eggs in water-filled tree holes, where its tadpoles develop into tiny frogs.

This poorly-known frog is only known from Kon Tum Province, central Vietnam.

Cloaked Moss Frog (Theloderma palliatum)

Rowley, Le, Hoang, Dau, and Cao, 2011

The Cloaked Moss Frog is so called because it has the remarkable ability to change from a “boring” (but probably quite practical) mottled brown at night to an amazing pale cream with dark chocolate brown spots. A species adapted for life in the trees, this species is only known from a handful of individuals (I don’t climb trees well!).

This frog species is only known from the high-elevation forests of the Lang Bian Plateau, southern Vietnam.

White-eyed Spadefoot Toad (Leptobrachium leucops)

Stuart, Rowley, Tran, Le, and Hoang, 2011

Asian Spadefoot Toads are known for their eyes. Some species have a bright scarlet upper iris, some completely black, and some blue. The White-eyed Spadefoot Toad, like its name suggests, has a strikingly white upper iris. The species breeds in clear, rocky streams in high-elevation cloud forests, and buries itself under the leaf-litter and mud on the forest floor in the dry season.

The White-eyed Spadefoot Toad is only known from the Lang Bian Plateau in southern Vietnam.

Bidoup Leaf-litter Toad (Leptolalax bidoupensis)

Rowley, Le, Tran, and Hoang, 2011

The quietest of all Leaf-litter Toads, you need to strain your ears to hear the faint call of the Bidoup Leaf-litter Toad. Like other extra-small Leaf-litter Toads, these frogs breed at in rocky seeps near streams.

The Bidoup Leaf-litter Toad is only known from the high-elevation cloud forests of the Lang Bian Plateau, southern Vietnam.

Vampire Flying Frog (Rhacophorus vampyrus)

Rowley, Le, Tran, Stuart, and Hoang, 2010

The Vampire Flying Frog is named after its tadpoles, which sport curved, black “fangs” in place of normal tadpole mouthparts. These “fangs” are thought to help the tadpoles survive in the tiny, water-filled tree-holes that they grow up in. Female Vampire Flying Frogs return to their young to feed them her unfertilized eggs. These eggs are wrangled into the tadpoles mouths with the help of their fangs.

The Vampire Flying Frog is only known from the high-elevation cloud-forests of Lang Bian Plateau in southern Vietnam.

Copper Leaf-litter Toad (Leptolalax aereus)

Rowley, Stuart, Richards, Phimmachak, and Sivongxay, 2010

The Copper Leaf-litter Toad was discovered by my colleagues in Laos, and I was lucky enough to be involved in describing the species. It’s most different from other Leptolalax in lacking the black markings a long the side of the head and body.

The species is only known from low elevation forests in southern Laos.

Orange-bellied Leaf-litter Toad (Leptolalax croceus)

Rowley, Hoang, Le, Dau, and Cao, 2010

A pretty spectacular Leaf-litter Toad, named after its bright orange belly (croceus is latin for “saffron-colored”). Males of the species were pretty adventurous for a Leptolalax, often climbing from the leaf-litter on the forest floor onto low ferns and shrubs beside a mountain stream to call. Listen to the advertisement call of the species.

So far, this species is only known from a patch of forest in the mountains of Kon Tum Province in central Vietnam.

Musical Leaf-litter Toad (Leptolalax melicus)

Rowley, Stuart, Neang, and Emmett, 2010

Looking very similar to Appleby’s Leaf Litter Toad, the Musical Leaf-litter Toad stood out mostly by it’s call. Like other species in this genus, males have a quiet call resembling a cricket. This little brown frog had a distinctly more melodious call than its relative, with males having an ‘introductory squeak’ before the normal chirping.

The Musical Leaf-litter Toad is only known from the forests of Virachey National Park, in northeastern Cambodia.

Appleby’s Leaf-litter Toad (Leptolalax applebyi)

Rowley and Cao, 2009

The first frog that I described, Appleby’s Leaf-litter Toad was the start of my obsession with the genus Leptolalax. Small, brown and near-invisible in the leaf-litter in which it lives, the call of this species also sounds remarkably like a cricket. I began to think I was wasting my time searching for an insect until I uncovered this little guy. Thankfully, my persistence paid off!

Appleby’s Leaf-litter Toad is known from the forests of Quang Nam and Kon Tum Provinces in central Vietnam.