Our Frogs, Toads and Turtles
Due to her location, climate and environment, Bangladesh is home to a wide variety of life-forms of all kinds. Among these, 45 species of frogs and toads and 29 species of turtles have been recorded here.
In the recently published book Amphibians and Reptiles of Bangladesh: A Field Guide, authors M. Kamrul Hasan, M. Monirul H. Khan and M. Mostafa Feeroz – professors at Jahangirnagar University - provide photographs and descriptions of most of these species (as well as many other reptiles.) The book provides interesting data about these animal orders and their place in the ecology of Bangladesh. For example, when frogs' legs were exported from here in the 1970s and 80s, the decimation of the frog population caused an increase in pests in our farmlands (since frogs live on insects.) The cost of importing surplus pesticide actually exceeded the revenue generated from exporting frogs' legs.
I also learned the differences between frogs and toads. Toads walk; frogs hop. Frogs have slimier skin and come in a variety of colours. Toads have rough, dry skin and bland colouring. Toads are usually bulkier and slower than frogs.
Our largest frog is the kola bang (Indian bull frog, hoplobatrachus tigerinus) which can reach up to six inches. Because of its large size, it is threatened due to consumption by some ethnic communities. Frogs and toads are polychromatic: they change their colour during breeding season in order to attract mates.
My favourite frog is the common tree frog. Its ability to jump so high whenever it is disturbed is certainly impressive and entertaining.
Speaking with Dr. Hasan about this work, I discovered that serious field-research on reptiles and amphibians in Bangladesh gained momentum only after 2007. Much work remains to be done. For example, Dr. Hasan suspects there are many more species of reptiles and amphibians in Bangladesh than are currently catalogued. We need to do more field work to find and identify them. Potential areas of exploration are the wild areas of Sylhet and Chittagong.
Several species shown in the book have names related to Bangladesh: for example, pangshura Sylhetensis (Sylhet roofed turtle), mycrohyla Mymensinghensis (Mymensingh mycrohid frog) and the Bostami turtle. I was under the impression that these were endemic to Bangladesh, that is, they can be found only in Bangladesh. However, Dr. Hasan corrected my mistake: there are no endemic species in Bangladesh. The names come from where the animals were caught first. For a long time, we thought that the Bostami turtle of Chittagong was the only endemic life form in Bangladesh, but later it was discovered living in Assam also.
The threats to our reptile and amphibian population come from habitat destruction and pollution. Water quality in our ponds and streams is critical, since frogs fertilize externally: females lay their eggs in water and the males drop sperm on them. Any pollution in the water can negatively impact this fertilization.
The book is a welcome addition to our natural history literature. We hope to see more exciting work from this team of researchers, the Wildlife Research Group of Jahangirnagar University.
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