Pre-monsoon rain could hit king cobra breeding in Karnataka

Experts fear the excess summer showers that lashed Tirthahalli, Sringeri and Hebri taluks during the king cobra breeding season could adversely impact the life cycle of the umbrella species of the Western Ghats.

Between March 1 and May 31, the three taluks saw nearly one-and-a-half to three times more than the normal rainfall. While the world’s largest venomous snakes are spread across the Western Ghats from Kerala to parts of Maharashtra, these three taluks in Shivamogga, Chikkamagaluru and Udupi districts respectively, are where research stations such as Agumbe Rainforest Research Station (ARRS) and Kalinga Foundation have been conducting regular studies. Perhaps these are the only centres dedicated to studying king cobras.

According to the Karnataka State Natural Disaster Monitoring Centre, Tirthahalli received 359 mm of rainfall between March 1 and May 31 against the average of 118 mm; similarly, in Sringeri, against the normal pre-monsoon showers of 196 mm in three months, the taluk received 321 mm and Hebri recorded 422 mm of summer showers against the normal rainfall of 200 mm.

Herpetologist P Gowri Shankar of the Kalinga Foundation said though there is not enough scientific evidence to link excess rainfall and cobra breeding, the heavy rains affect the nest building process as the female king cobras do not get dry leaves.

“When I first started studying these king cobras in 2005-06, we used to get information of four to six nests from April to July. However, they are down to one to two. This is a worrying trend,” he said.

King cobras are the only snakes known to build a nest. The core of the nest, where 25-30 eggs are laid, must maintain a temperature 26–28 degrees Celsius for 75-90 days for incubation, which is difficult with wet leaves.

Ajay Giri of ARRS says wet leaves result in fungus growth on eggs, thus destroying them.

Normally, of the 30 eggs, only one or two hatchlings survive till adulthood.

Sources in the Forest Department confirmed to DH that a fortnight ago they found an abandoned king cobra nest near a house in Uttara Kannada district where nearly 22 of the 26 eggs had fungus and the survival of the remaining eggs was also doubtful. The core of the nest was completely wet due to heavy rains, said an officer.

Pre-monsoon showers

Gowri Shankar said king cobras are used to pre-monsoon showers.

“However, what we are witnessing for the past few years is erratic and excess rainfall caused by climate change. The king cobras, which are the topmost predators in the Western Ghats among reptiles, may not see sudden variations in their population.

However, if this change in rain pattern continues, then the future of these snakes will become uncertain,” he said.

Dampener

• King cobras are the only snakes to build a nest

• 25-30 eggs are laid at a time

• Normally, one or two hatchlings survive

• Incubation period: 75-90 days

• Temperature required: 26–28 degrees Celsius

• With wet leaves, this cannot be achieved