12 May 2014

How animals beat the heat

There's always thirst-quenching food around to tackle the summer heat. And, this squirrel seems to have found it!

  • Wild animals are wired to handle the heat
    PAUL NORONHA Wild animals are wired to handle the heat
  • There's always thirst-quenching food around to tackle the summer heat. And, this squirrel seems to have found it!

Summer is here. How do insects, birds and animals in the wild deal with soaring temperatures? Akila Kannadasan finds out that the trick lies in effortless adaptation

This summer, Urigam, Asokan, and Giri, the elephants of Arignar Anna Zoological Park, Vandalur, will be given special treatment to beat the heat. At 3 p.m. every day, they will be given shower baths to cool off. In the wild, the elephant knows how to deal with the heat. So does the little red ant. The hyena has his own plans. Every inhabitant of the forest has his / her way of handling the summer heat.
So, what exactly happens inside a forest during the summer? Everything, from the blades of grass by the brush, to the neighbourhood waterhole, wears a new look for the season. The inhabitants too, undergo changes in their lifestyle. Animals have been dealing with dry spells and droughts since time immemorial. But what’s fascinating is how they do so.
“Red ants burrow deep into the soil to escape the heat,” says naturalist ‘Poochi’ Venkat. “Most insects that come out for nectar, wind up early.” Insects however, prefer humid to dry weather. But they cannot afford to expose their wings too much in the heat. Venkat says that the wings have to be well-moisturised in order to be supple.
Insects alter their comings and goings as per the weather. When the day is hot, they “retire earlier than usual”. For instance, an insect that usually floats by lazily till late in the day, will probably come out early and go home by 8.30 a.m. to escape the heat. Some insects such as the beetle and leaf spider dare not come out when the sun is out, adds Venkat.
Animals too change their activity patterns during the summer, says biologist R. Arumugam. “They restrict their activity to early mornings and late evenings,” he says.
Birds try not to spend too much time in the heat, says P. Pramod of Salim Ali Centre for Ornithology and Natural History. Since birds are warm-blooded, they react to heat much like humans. “During summer, migratory birds fly back to the Himalayas and Siberia. Resident birds will be relatively less active during the peak hours of the day,” he adds.
Wildlife conservation filmmaker Shekar Dattatri feels that “animals that have evolved in the tropics are well able to withstand summer temperatures”. Tigers, for instance, “often soak themselves in a river or waterhole for sometime and then lie in the shade during the hottest part of the day. They may also seek shelter in a cave or a thicket.” While tigers “prefer hunting at night, early morning or late evening,” Dattatri says that he has seen, on occasion, tigers “hunt during the middle of a hot summer day” when necessary. The animals might also hunt about water sources during the dry season, he adds. For, they know that herbivores will be drawn to water.
Dattatri says that “most animals get sufficient moisture from the food they eat and do not need copious quantities of water”. But elephants, however, “require nearly 100 litres of water each, a day”. “Generally, with the advent of the dry season, elephants move away from dry areas and into areas where there are reliable sources of food and water, such as streams, rivers, lakes and even reservoirs. Most forests have some perennial sources of water, which provide for animals.”
Elephants have a unique way of warding off heat. Dattatri explains that they “regulate their body temperature by fanning their large ears, which have a network of blood vessels. The flapping cools the blood passing through the ears and thus cools the body. In effect, the ears of elephants act like radiators. Elephants also love to bathe in water or splash themselves with water with their trunks, and this is another way they keep cool.”
The Forest Department is augmenting water resources in forest areas for the dry season. For 2013-2014, Department records suggest that the Tamil Nadu government has sanctioned Rs. 2.81 crore to install motors energised by solar power that will supply water in forest areas. Thirty such systems have already been installed. Waterholes are also being replenished during the summer. Dattatri believes that this practice “is a matter of some debate. Many leading ecologists feel that this is misplaced compassion and should not be done indiscriminately or as a matter of routine”.
Perhaps humans tend to think animals suffer the heat the same way they do? “People tend to compare themselves with animals. But the eco-system is different,” says a Forest Department official. “A deer can quench its thirst by eating a stem or a leaf. Another animal can do so by debarking a tree…” Animals know how to take care of themselves, he feels. They have been wired to do so.
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* Summer plans at Arignar Anna Zoological Park, Vandalur
* Sprinkler facilities to be introduced at zebra, giraffe, and ostrich enclosures
* Wet gunny bags to be suspended around bird enclosures; these will be periodically moisturised
* Shower facilities to be provided for birds
* Watermelon, tender coconuts, and cucumber to be included in the diets of birds and animals

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