Forty Precious Winks

//

Dr. A.A. Quraishy

Sleep is an essential part of life, but different animals have different sleeping habits. Some animals sleep for several months, while certain birds remain in flight for long periods without resting.

About a fortnight ago FM 100 in their popular ‘Breakfast show’ asked which animal slept the least. It was tough. Most of our M.Sc., in Zoology will not know. For two days most answered ‘the elephant’, and at last when someone correctly answered its collateral question about Wahid Murad, out exploded the musical approval with the riotous hullabaloo, whistles, clapping followed by the most sought-after announcement “you are right.”

I wrote to them that it was not right arguing that I have timed elephants sleeping in Karachi Zoo where they lay prone like a baby on the side, snored and snoozes for at least an hour when one woke up at the slight click of a twig that broke under my foot.

Even in medicine the term ‘dolphin sleep’ is used to describe a short, snappy sleep that comes and goes in a moment because dolphins, being mammals, like us, sleep briefly, say 2-3 minutes, waking up and coming up to breath air at the surface of the sea, as they have lungs and not gills as in fish. They again go to sleep, awake, sleep and so on. In the morning they are fresh; there is no hangover. Sprite and buoyant they skip, hop and jump as usual.

Which prompted me to write about one of the most difficult questions on sleep behaviour in wild animals. Some sleep like logs for weeks or months (one of them sleeps for 9 months out of the 12), without eating and drinking during hibernation in prolonged dark winter. Arctic tern, a bird, flies every year to the South Pole past the Cape Good Hope, covering a distance of about 24,000 miles and will not sleep while flying over vast expanse of the oceans.

The American Golden Plover, a small bird the size of our common pigeon breeds in Alaska and the Arctic. It flies to South America, going as far as New Zealand before returning to the breeding ground in the spring. In little more than six months, it covers, 15,000 to 17,000 miles. No one knows for sure when and how does it sleep.

The common swift remains aloft for at least nine months at a stretch, possibly much longer, some scientists say, it, some-how, manages to get enough rest during the night flight. Fantastic indeed, that a small bird, the size of our house sparrow can fly without sleep for nine months and still be healthy and alive. It must for sure feeding on the insects in the air, otherwise the constant wing beat can never go on for such long time without proper energy and fuel. It is not fuelled by a slow burning nuclear material. Eat it must, but sleep? Well your guess is as good as mine.

The sooty tern, a bird of the saline area after leaving the nestling grounds does not come to land or alight on water until it returns to its breeding grounds on tropical or sub-tropical islands in the Pacific, Atlantic or Indian ocean for the first time at the age of three or four years! Incredible but true. Where is the sleep, rest, food and the repair of the body? I would not have believed it either had I not read the information from the most reliable sources.

Our heart too works without rest much before the child is born. But if it stops to rest the person will die. Its sleep-period is designed to be completed between one beat and the other.

To add confusion to this issue, read this: the longest recorded period for which a person has voluntarily gone without sleep is 18 days and 17 hours by Mrs Maureen Weston of Peterborough, Cambridgeshire England. An extreme case of Mr Valentine Medina Poves of Cuenca, Spain who lost all his sleep and did not sleep until his death several decades later. During the day he worked in his farm and at night to patrolled the village as watchman.

Now we take the case of hedgehog, a small spiny mammal that moves out at night and when touched rolls into a ball to protect it. It is also found in the area where it snows and the temperature falls below the freezing point and remains so for months.

When he is active its body temperature is about 36 degrees C. When it sleeps in long winter his temp. falls to 6-7 degrees. The respiration goes very slow and its legs and feet are quite cold. The sleep resembles the sleep of death yet the brain and the nervous system are at work.

Research has shown that no warm-blooded animal like a polar bear can sleep for six months without rousing. It must get up to rid the poisons or wastes accumulated in the body. Our bears, squirrels and marmots in the extreme north of Pakistan, as in Balochistan, sleep briefly, some deeper and longer than the other. The food is scarce and buried under the snow.

The most extreme form of hibernation is found in the Barrow ground squirrel of Alaska which packs a year of life into three months’ living. Sleeping for nine months without exercise and still remaining healthy is a mystery like so many other secrets of life that remains yet undeciphered.

Now a knockdown. An alligator’s heart, in hibernation, beats once in ten minutes and yet in summer he gets up, catches a deer, drags it down to drown with its heartbeat reaching 80 a minute.

The camel because of his adaptation to be able to survives in desert, changes his body temperature four times in twenty four hours!