When people think of animals threatened with extinction, they often think of pandas, tigers and primates- with reason. But as a group, it’s actually amphibians and not mammals that are the most imperiled. A staggering one-third of the roughly 7,000 known amphibian species are threatened with extinction. Frogs, toads, salamanders and the lesser-known caecilians (burrowing, worm-like amphibians) are undergoing such dramatic declines that they’ve been heralded as leading the way in Earth’s “sixth mass extinction”.
In many countries, the plight of amphibians has deservedly received a great amount of scientific and public attention, but Southeast Asian amphibians have been almost entirely overlooked. Because of this, you might be forgiven in thinking that there’s nothing to worry about. But the situation couldn’t be further from the truth. Confronted with the highest deforestation rate on the planet, and huge over-harvesting pressure (amphibians are harvested for food, traditional medicine and pets), Southeast Asian amphibians are being driven towards an extinction crisis.
At present, almost one-fifth of Southeast Asian amphibians are listed as threatened, and the amphibians of the region remain so poorly-known that we don’t even know how many amphibian species there are in Southeast Asia! Current estimates of amphibian species numbers are serious underestimates, with new species being continuously discovered. For example, over a quarter of amphibian species known from Vietnam, Laos and Cambodia have been described since 2000, and discoveries continue at a rapid rate.
For the amphibians that are currently known from Southeast Asia, we lack even information for most species. 36% of all amphibian species recorded from Southeast Asia are so poorly known that we don’t know enough about them to even know if they are threatened or not! This is 11% higher than the global average for amphibians. Geographic distributions are also poorly known, with many species known only from a single location, and large areas in Southeast Asia remain unsurveyed for amphibians. Our lack of knowledge of this highly threatened group of animals hinders even the most basic amphibian conservation in Southeast Asia.
My research strives to gain a better understanding the diversity and conservation status of amphibians in Southeast Asia and to facilitate long-term amphibian biodiversity conservation. I work with an amazing group of passionate researchers and students. Several of the younger team members were introduced to amphibians via Amphibian Research and Conservation training courses I developed in order to introduce young biologists in Southeast Asia to amphibian research and conservation. Since 2006, I have conducted five of these training courses in Southeast Asia. I strongly believe that training young regional scientists is essential for long-term amphibian conservation.
Central to my research are scientific expeditions to often remote, unexplored, montane forests. So far, I have led 22 expeditions in search of amphibians in Southeast Asia. These expeditions have resulted in the discovery of 14 new amphibian species.
Our discoveries include the bizarre Vampire Flying Frog (Rhacophorus vampyrus), a species with fanged tadpoles, and the tiny Quang’s Tree Frog (Gracixalus quangi), with males that sing like birds rather than frogs. Three small, brown Leaf-litter Toads have also been named in honour of ADM’s Rob Appleby, Denys Firth and Chris Botsford (Leptolalax applebyi, Leptolalax firthi and Leptolalax botsfordi). These discoveries are just the tip of the iceberg.
Most recently, my colleagues and I came across a rather average-looking, brown frog with a truly remarkable ability. During field-work at Nantu Forest, Sulawesi, my colleague Dr Mirza Kusrini and her students came across an unusual frog. Rumored to have existed for several decades, in their hands they held a bizarre frog- a frog that gives birth to tadpoles, instead of simply laying eggs. The species (Limnonectes larvaepartus) has internal fertilisation (which only a handful of frogs in the world do). The female then holds the tadpoles in her oviducts (we found over 100 in one female!) until they are relatively large and well-developed. When the tadpoles can no longer fit in the female, they are deposited in streams to continue their development as normal, feeding tadpoles.
Finding the only known frog that gives birth to tadpoles, and discovering more than a dozen new species of amphibian, highlights just how little we know about amphibians overall. It also reminds us how much remains to be discovered from the imperiled forests of Southeast Asia, hopefully in time to ensure its long-term conservation.
All this work would not have been possible without the incredibly generous support of ADM Capital Foundation.
Written by Dr Jodi Rowley
Kusrini, M.D., Rowley, J.J.L., Khairunnisa, L.R., Shea, G.M. & Altig, R. (2015) The reproductive biology and larvae of the first tadpole-bearing frog, Limnonectes larvaepartus. PLoS ONE. 10(1): e116154.
Photos by Jodi Rowley and Fata Habibburahman