Thermometer Bird !

S Balakrishnan *

The Thermometer Bird seemed agitated; 'How dare you write about me ?' it questioned me. 'You sighted neither me nor even my mound nest when you visited my territory. Then on what authority and moral ground do you plan to write?' The Megapode bird grilled me. I was amazed by the all-knowing bird's idea about my 1979 trip to its territory in Great Nicobar Island, India's southernmost land mass.

But then I was obsessed of visiting that Island's southern point, Parson's Pygmalion Point which is also India's real southernmost point (later renamed Indira Point) that nothing else mattered to me, I accepted my mistake.

But I love you so much, you know ? I assuaged the ruffled feathers/feelings of the bird. 'You love me or my curry and my eggs ?' it retorted.

"Oh, believe me; I am from a pure vegetarian family. You are so unique that I want to 'educate' the whole world about you," I tried to please the bird. At last it relented and approved my proposal with a curt "May proceed''.

As a show of gratitude I will fight to declare Megapode as the State bird of the Union Territory of Andaman & Nicobar Islands. Hope the Andaman Wood Pigeon (Columba Palumboides) doesn't get upset for dethroning its status and start pecking my bald head.

The Nicobar Megapode bird's zoological name is Megapoidus freycinet Nicobariensis. Oh, forget it; let us simply call it Megapode, the bird with big (Mega) claws (pode). So, now you know why it is called Megapode ! The Nicobari people call it 'Kongah' in local parlance. Nicobar Megapode prefers dry deciduous forest along the sea coast.

The family of Megapodidae includes 7 genera and 12 species of Australasian chicken-like birds (order Galliformes) that bury their eggs to hatch them. Based on physical features and size they are divided into 3 major groups. Of these, the Nicobar Megapodes come under the Scrub Fowl (Megapodius) type which is also found in the Philippines, Pacific Islands, New Guinea, Indonesia, Malaysia and northern Australia.

Megapodes are more or less the size of domestic fowls, some species slightly smaller or bigger. They are omnivorous (eat both plant-based and animal-based foods) and are usually found at ground level; they can run fast and, if necessary, also fly for short distance.

Megapodes are unique because they incubate their eggs in mounds which they manipulate to regulate the temperature within; hence the names Incubator Birds, Mound-builders and Thermometer Birds. It is the only bird that uses external heat source, and not its own body heat, to hatch its eggs.

Most of these species depend on fermenting vegetative matter to produce the heat necessary for incubation, while some as well use solar and volcanic action heat to hatch their eggs. The Nicobar scrub fowl Megapode builds the mound with sand, decayed vegetative matter like leaves, sticks, etc.

Though Megapode is small in size – only as big as domestic fowl – it builds a mound of such a vast size that it could go up to 4 ft. in height and 15 ft. in dia ! It is the duty of male Megapode to build the mound while the female encourages (or nags). Megapodes of another group build mounds of 10 meters diameter!

The parent birds maintain the temperature within the mound evenly at 33° C (91° F) by closing and opening various vents of the mound nest. They use the beak to measure and correct the temperature of the mound. How smart of them !

The Megapode eggs are 11 cm long and weigh as much as 270 gms (1/4 kg!) which is 5 times bigger than a domestic hen's. So it weighs 16% of an adult Megapode's body weight, the highest egg : body weight ratio !

In the fowl family the ratio is usually just around 3% only. The incubation period is a long 75-80 days compared to the 21 days of a hen's. A pit of 1.5 ft. is first dug to lay the eggs which are then covered by the mound built by male.

The eggs are laid vertically (broad end up) for better development of embryo and head up position for digging out of the pit and mound. The hatchlings fly immediately after coming out and are independent from then onwards itself ! In some species a few females lay their eggs together in the same pit.

In India, Megapode is endemic to Nicobar where also it is found only in some Islands of the Nicobar Group. It has been declared an endangered species in India. Monitor lizard is the predator besides humans who find its big eggs a wholesome food.

Besides, it is believed to have aphrodisiac properties, hence more susceptible. The bird itself is not that attractive which is a plus point, but as the mounds are too big the eggs fall an easy prey to the humans.

Nicobar Megapodes may number around 1000 but figures vary as it is a shy bird that hurries into the bush. For the time being it is safe in the Great Nicobar Biosphere Reserve but danger is looming. NITI Aayog has recently proposed plans for development of this tail-end territory of India into a port city like Singapore or Hong Kong, to counter China's expansionist plans in the Indian Ocean.

Megapode was honoured by an Indian postal stamp issued in 2012. Long Live Megapoidus freycinet Nicobariensis, aka Thermometer Bird!