With mercury surging to record levels this month, Bhopal residents are experiencing a unique experience that of hundreds of big bats dropping dead from trees.
But the 32 sq km expanse of the Upper Lake in the city is giving these bats a chance to beat the heat and survive, experts say.
Thousands of these bats-- known as Indian flying fox or fruit bat-- are seen rushing to the lake to belly-dip in the water to cool their heat exhausted bodies.
HT has captured the unique occurrence on camera as residents flocked to the lake to witness the spectacle.
Unlike the insect-eating bat species, these large Indian flying foxes do not roost in caves, tree-hollows and old buildings.
They roost in large colonies on the exposed branches of big trees during the day and forage at night for ripe fruits and blooming flowers.
Their exposure to the sun makes them susceptible to heat-stress during peak summer, says Ornithologist Sangeeta Rajgir.
When temperatures cross 43 to 45 degrees Celsius and there is a heat wave, the fruit bats fail to regulate their body heat and as a result a large number of them die, she said.
“The Upper Lake, which is one of the largest man-made lakes in India, is proving to be a lifeline for the bats,” Rajgir, who runs Bhopal Birds, an NGO, told Hindustan Times.
Bats are warm blooded flying mammal, which like humans, face problems when the temperatures rise beyond 45 degrees Celsius and there is a heat wave.
“The bats become victims of heat strokes, which prove fatal for many of them, especially in case these bats that roost on exposed branches and not in caves. Due to the heat wave, they suffer hyperthermia and dehydration, which results in their death, ” she said.
“In Bhopal, these fruit bats roost during day time on the big trees in the Kamla Park area near the Upper lake and in Kerwa area on the outskirts the city,” she added.
On why the bats belly-dip in the Upper Lake, Rajgir said it was one of the animal’s mechanisms to cope up with the heat.
“When heat wave sweeps the trees, they generally start cooling their bodies by continuous fanning of their large wings. The bat belly-dip in the water to cool and rehydrate itself from the scorching heat, ” she said.
According to experts, the Indian flying fox (Pteropus giganteus) is listed under Schedule V of the Indian Wildlife (Protection) Act and is found across the Indian subcontinent.
Its daytime roost sites are generally permanent, from which they have been known to fly as far as 100 to 150 km in search of fruits during nighttime.