EDGE Community

Project information

[Project name/title]
Ecology of the purple frog in the Western Ghats, India

[Project description/overview]
This project aims to discover more about the ecology of this elusive and recently described frog.

Western Ghats, India.

Project type:
Scientific research

Relevant EDGE species:
Purple frog (Nasikabatrachus sahyadrensis)

Project members:
Karthikeyan Vasudevan

Relevant species
4. Purple frog (Nasikabatrachus sahyadrensis) EN

Described in 2003, this species is the sole member of the first new frog family to be discovered since 1926!

[Relevance description]
The purple frog is relic species of an ancient lineage of frogs in the world. After its discovery in 2003, there have been no studies on the ecology of the species.

This study aims at documenting the natural history, distribution and population of this rare fossorial frog.
The Western Ghats mountains extend for nearly 1600 km (from 8˚N to 21˚N) almost along the west coast of India, and covers about 160,000 km. Nearly 130 species of amphibians occur in this area, including several newly described ones, with about 75% endemism. Nearly 90% of the species have been reported to occur in rainforest. Among reptiles nearly 60% of all species from the region are endemic. Many vertebrates groups from this region are single representatives of a genus or even a family.

These propositions prompt two questions: what are the factors that cause many vertebrates to become specialized in the Western Ghats? what are the factors that lead to higher taxonomic order diversity in the region? These answers to these questions can have enormous conservation implications to the Western Ghats and further our understanding on the evolution endemism in tropical habitats. These questions can be answered in more ways than one, and I have chosen amphibians and reptiles as the focal organisms to gather information on their ecology, biogeography and phylogeny in order to answer the questions.

The present study is a satellite project of this larger initiative, where ecology, distribution and specialization of the purple frog will be studied.
Project summary
The study has documented the natural history of the purple frog. The purple frog is fossorial and emerges on the surface to breed within a short period before the onset of the monsoon rains in the southern Western Ghats each year. They are explosive breeders and the onset of breeding is marked by loud vocalizations by males from beneath the surface of the soil.

Amplexus and egg laying coincides with initial south west monsoon showers in the southern Western Ghats. Eggs are laid in both seasonal and perennial forest streams. The larvae grow and metamorphose on large rocks with water flowing over them in the forest streams.

Since the purple frog emerges for a short time period on the surface, conventional methods of documenting their abundance might not be feasible. Therefore, an automated vocalization recorder for the purple frog is being developed. Designing and lab trials are currently underway. Once the recorder will be made field worthy, desired number of recorders will be fabricated. Finally, the recorder will be deployed in the forest to obtain information on the purple frogs’ distribution in different habitats, emergence and breeding behaviour. The breeding behaviour, larval morphology, developmental history of the purple frog will also be studied.
Start date: January 2008
Duration: 2 years
Project members
Dr Karthikeyan Vasudevan : Coordinator and field scientist

Karthik is the coordinator and field scientist of a project which aims to find out more about the elisive purple frog.

[Member role description]
[Title:] Purple frog - metamorph
[Image caption]
Nasikabatrachus sahyadrensis
[Title:] Organisation
[Image caption]
Wildlife Institute of India
[Title:] Purple frog - adult
[Image caption]
Nasikabatrachus sahyadrensis
[Title:] Purple frog - tadpoles
[Image caption]
Nasikabatrachus sahyadrensis