Unique Facts

They don’t change colour to match the background. Never have; never will. Complete myth. Utter fabrication. Total lie. They change colour as a result of different emotional states. If they happen to match the background it’s entirely coincidental. Chameleons change colour when frightened or picked up or when they beat another chameleon in a fight. They change colour when a member of the opposite sex steps into view and they sometimes change colour due to fluctuations in either light or temperature. A chameleon’s skin contains several layers of specialised cells called chromataphores (from Greek chroma, colour, and pherein, to carry), each with different coloured pigments. Altering the balance between these layers causes the skin to reflect different kinds of light, making chameleons a kind of walking colour-wheel. read more : How do pearls form? 10 interesting Facts about The Eiffel Tower How do lemmings die? Why is the coast eroding? How do lemmings die? It’s odd how persistent the be...

Not by mass suicide, if that’s what you’re thinking. The suicide idea seems to have originated in the work of nineteenth-century naturalists who had witnessed (but not understood) the four-year boom-and-bust population cycle of the Norwegian lemming (Lemmus lemmus). Lemmings have a phenomenal reproductive capacity. A single female can produce up to eighty offspring a year. Sudden surges in their numbers once led Scandinavians to think they were spontaneously generated by the weather. What actually happens is that mild winters lead to overpopulation that in turn leads to over-grazing. The lemmings set off into unfamiliar territory in search of food until they pile up against natural obstacles like cliffs, lakes and seas. The lemmings keep coming. Panic and violence ensue. Accidents happen. But it isn’t suicide. A secondary myth has evolved which is that the whole idea of mass suicide was invented by the 1958 Walt Disney film White Wilderness. It’s true that the film was a complete fake....

Not a goldfish, for starters. Despite its status as a proverbial fact, a goldfish’s memory isn’t a few seconds long. Research by the School of Psychology at the University of Plymouth in 2003 demonstrated beyond reasonable doubt that goldfish have a memory-span of at least three months and can distinguish between different shapes, colors and sounds. They were trained to push a lever to earn a food reward; when the lever was fixed to work only for an hour a day, the fish soon learned to activate it at the correct time.  A number of similar studies have shown that farmed fish can easily be trained to feed at particular times and places in response to an audible signal. Goldfish don’t swim into the side of the bowl, not because they can see it, but because they are using a pressure-sensing system called the lateral line. Certain species of blind cave fish are able to navigate perfectly well in their lightless environment by using their lateral line system alone. While we’re dealing wi...

About two years. On 10 September 1945, a plump young cockerel in Fruita, Colorado, had his head chopped off and lived. Incredibly, the axe had missed the jugular vein and left enough of the brain stem attached to the neck for him to survive, even thrive. Mike, as he was known, became a national celebrity, touring the country and featuring in Time and Life magazines. His owner, Lloyd Olsen, charged twenty-five cents for a chance to meet ‘Mike the Headless Wonder Chicken’ in sideshows across the USA. Mike would appear complete with a dried chicken’s head purporting to be his own – in fact, the Olsens’ cat had made off with the original.  At the height of his fame, Mike was making $4,500 a month, and was valued at $10,000. His success resulted in a wave of copycat chicken beheadings, though none of the unfortunate victims lived for more than a day or two. Mike was fed and watered using an eyedropper. In the two years after he lost his head, he put on nearly six pounds and spent his ti...

The ostrich. Although it is the largest single cell in nature, an ostrich egg is less than 1½ per cent of the weight of the mother. A wren’s egg, by comparison, is 13 per cent of its weight. The largest egg in comparison with the size of the bird is that of the Little Spotted kiwi. Its egg accounts for 26 per cent of its own weight: the equivalent of a woman giving birth to a six-year-old child. An ostrich egg weighs as much as twenty-four hen’s eggs; to soft-boil one takes forty-five minutes. Queen Victoria tucked into one for breakfast and declared it among the best meals she had ever eaten. The largest egg laid by any animal – including the dinosaurs – belonged to the elephant bird of Madagascar, which became extinct in 1700. It was ten times the size of an ostrich egg, nine litres in volume and the equivalent of 180 chicken’s eggs. The elephant bird (Aepyornis maximus) is thought to be the basis for the legend of the fierce roc that Sinbad battles in the Arabian Nights.

It’s a mushroom. And it’s not even a particularly rare one. You’ve probably got the honey fungus ( Armillaria ostoyae) in your garden, growing on a dead tree-stump. For your sake, let’s hope it doesn’t reach the size of the largest recorded specimen, in Malheur National Forest in Oregon. It covers 890 hectares (2,200 acres) and is between 2,000 and 8,000 years old. Most of it is underground in the form of a massive mat of tentacle-like white mycelia (the mushroom’s equivalent of roots). These spread along tree roots, killing the trees and peeping up through the soil occasionally as innocent-looking clumps of honey mushrooms. The giant honey fungus of Oregon was initially thought to grow in separate clusters throughout the forest, but researchers have now confirmed it is the world’s single biggest organism, connected under the soil. STEPHEN What, or which, is the largest living thing on earth? BILL France.

Mauna Kea, the highest point on the island of Hawaii. The inactive volcano is a modest 4,206 m (13,799 feet) above sea level, but when measured from the seabed to its summit, it is 10,200 m (33,465 feet) high – about three-quarters of a mile taller than Mount Everest. As far as mountains are concerned, the current convention is that ‘highest’ means measured from sea level to summit; ‘tallest’ means measured from the bottom of the mountain to the top. So, while Mount Everest, at 8,848 m (29,029 feet) is the highest mountain in the world, it is not the tallest. Measuring mountains is trickier than it looks. It’s easy enough to see where the top is, but where exactly is the ‘bottom’ of a mountain? For example, some argue that Mount Kilimanjaro in Tanzania – at 5,895 m (19,340 feet) – is taller than Everest because it rises straight out of the African plain, whereas Everest is merely one ofmany peaks topping the enormous base of the Himalayas, shared by the world’s next thirteen highest mo...

It’s on Mars. The giant volcano Mount Olympus – or Olympus Mons in Latin – is the highest mountain in the solar system and in the known universe. At 22 km high (14 miles) and 624 km (388 miles) across, it is almost three times the height of Mount Everest and so wide that its base would cover Arizona, or the whole of the area of the British Isles. The crater on the top is around 72 km (45 miles) wide and over 3 km (nearly 2 miles) deep, easily big enough to swallow London. Mons Olympus doesn’t conform to most people’s idea of a mountain. It is flat-topped – like a vast plateau in a sea drained of water – and its sides aren’t even steep. Their slight incline of between one and three degrees means you wouldn’t even break sweat if you climbed it. We traditionally measure mountains by their height. If we measured them by their size, it would be meaningless to isolate one mountain in a range from the rest. That being so, Mount Everest would dwarf Olympus Mons. It is part of the gigantic Hima...

The Western Highlands of Kenya in Africa. In terms of annual downpour, Kericho in Kenya has more hail than anywhere else on earth, since it falls on average 132 days each year. By comparison, the UK averages only fifteen hail-days in a year and the worst affected area in the US, the eastern Rockies, experiences an average of forty-five haildays a year. What causes the abundance of hail is not fully understood. Kericho is the home of Kenya’s tea plantations, and a 1978 study showed that organic litter from the tea plants gets stirred into the atmosphere, where it acts as a nucleus around which hailstones can grow. Another theory is that the high altitude of the region could be to blame, as the shape of the terrain causes a large uplift of warm air which quickly condenses. This, and the reduced distance between the freezing level (about 3 miles up) and the ground, reduces the chance of hailstones melting. The average hailstone is about quarter of an inch across, but they can grow large e...

Antarctica. Parts of the continent have seen no rain for two million years. A desert is technically defined as a place that receives less than 254 mm (10 inches) of rain a year. The Sahara gets just 25 mm (1 inch) of rain a year. Antarctica’s average annual rainfall is about the same, but 2 per cent of it, known as the Dry Valleys, is free of ice and snow and it never rains there at all. The next-driest place in the world is the Atacama Desert in Chile. In some areas, no rain has fallen there for 400 years and its average annual rainfall is a tiny 0.1 mm (0.004 inches). Taken as a whole, this makes it the world’s driest desert, 250 times as dry as the Sahara. As well as the driest place on earth, Antarctica can also claim to be the wettest and the windiest. Seventy per cent of the world’s fresh water is found there in the form of ice, and its wind speeds are the fastest ever recorded. The unique conditions in the Dry Valleys of Antarctica are caused by so-called katabatic winds (from t...

Four. Two you can see; two you can’t. This discovery came from observing how fish breathe. Fish get their oxygen from water. Most of them have two pairs of nostrils, a forward-facing set for letting water in and a pair of ‘exhaust pipes’ for letting it out again. The question is, if humans evolved from fishes, where did the other pair of nostrils go? The answer is that they migrated back inside the head to become internal nostrils called choannae – Greek for ‘funnels’. These connect to the throat and are what allow us to breathe through our noses. To do this they somehow had to work their way back through the teeth. This sounds unlikely but scientists in China and Sweden have recently found a fish called Kenichthys campbelli – a 395- million-year-old fossil – that shows this process at its half-way stage. The fish has two nostril-like holes between its front teeth. Kenichthys campbelli is a direct ancestor of land animals, able to breathe in both air and water. One set of nostrils allo...