RAINFALL DEFICIT IN WESTERN GHATS (Syllabus: GS Paper 3 - Env & Eco)

Context: Erratic and deficit rainfall in monsoon 2023 in the Western Ghats have affected the breeding cycles of amphibians, showed recent visits by researchers.

Key Points

• Animals usually found abundantly in the region during the season have been absent.
• Rainfall results in the formation of temporary rock pools and replenishment of the permanent water bodies where frogs breed.
• The temporary pools require water to last for a few days depending on species’ larval period to enable frogs to breed and give birth to the newer generation.
• However, in the northern Western Ghats, water remains in some pools for only two to three days under short-duration rainfall. 
• Frogs lay eggs in this period but they dessicate or dry up before the tadpoles metamorphose into adults, as the pools lose water and moisture essential to complete the breeding cycle.
• The researcher has also noticed numbers of Malabar gliding frogs dwindling. 
• The Malabar gliding frogs were seen breeding abundantly about five years ago.
• Only a few pairs were found breeding and very few eggs were laid this year. 
• Certain species of frogs follow different strategies for breeding. Some species complete it in 2-3 days while others continue for 2-3 months.
• For example, Indirana species endemic to Western Ghats start breeding early. They lay eggs in moisture laden or damp conditions.
• Another species Xanthophryne tigerina or the Amboli toad breeds only for two to three days in a year and lives in lateritic rock, commonly found in tropical regions.