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Being afraid of the dark is totally normal
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Even though being afraid of the dark sounds childish, our fear of the dark is an evolutionary trait that we picked up to survive real-life predators stalking the night. Researchers have hypothesised that this innate fear stems from a point of human history when we were nowhere near the top predators we are today. Humans only really became super predators with the advent of technology, which wasn’t that long ago. Before technology, our ancestors were constantly on the look-out for predators that wanted nothing more than to chow down on human sandwiches. To make that even scarier, most of these predators hunted at night - a time of day when we are especially vulnerable to attack because of our relatively poor eyesight. This means that it was ...
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13160 |
duddy |
8 years ago |
Birds with purple crowns
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These beautiful birds are called purple-crowned fairy wrens, endemic to northern Australia. The picture was taken by ornithologists (bird banders) studying the birds as part of population monitoring in Australia. The way they are holding them is called "photographer's grip" which gently secures the legs while keeping the rest of the bird free. Handling time is generally very short.
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5938 |
duddy |
10 years ago |
Birthmarks and what causes them
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Birthmarks are congenital marks on the skin that appear at birth and occasionally disappears spontaneously. The term nevus refers to a benign cutaneous tumor consisting of blood capillaries. Such tumors, which rarely spread from their original site and are not dangerous, vary in color according to whether the capillaries composing them carry arterial or venous blood. The popularly termed cherry marks and port-wine stains (shown below) are nevi on a level with the surface of the skin. Certain other vascular nevi, commonly known as strawberry or raspberry marks (scientifically known as hemangiomas), are slightly elevated above the surface. These can appear anywhere on the body's surface, including the airway within the nose. The former Soviet ...
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5146 |
bio_man |
2 years ago |
Blood of Heroes from ancient times
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Elafonisi Beach on the Greek island of Crete has pastel pink sand! That rosy hue is caused by tiny particles of pink shells and coral that have been ground down over many years of erosion.
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5479 |
duddy |
9 years ago |
Blue blood is quite costly
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Did you know one quart of horseshoe crab blood costs $15,000 dollars? The critter's blue blood is a sort of bacteria killing machine that clots around ‘invaders’, eliminating them and protecting horseshoe crabs from lethal infections. Researchers have been harnessing the power of this blue blood to test medical supplies for contamination.
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3716 |
savio |
10 years ago |
Breast milk varies depending on gender
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Studies in humans, monkeys and other mammals have found that mothers have different breast milk 'recipes' depending on the sex of their newborn – boys often get milk that's richer in fat or protein, while baby girls get higher calcium levels and more milk overall. These findings could help improve baby milk formulas.
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3351 |
duddy |
10 years ago |
Bullying is an effective evolutionary strategy
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Bullying is not easy to define, namely because there is no one way to bully. It comes in many forms, from physical playground scuffles to verbal attacks. Even governments have a hard time defining it, often referred to as a repeated behaviour with the intent to hurt someone either physically or emotionally. By this definitions, there are many ape and monkey bullies, too. In fact, any hierarchical society is likely to have bullies in its midst. An unfortunate monkey at the bottom of the hierarchy is repeatedly attacked and picked upon by those higher up in the group - they are sometimes beaten up every day. Bullying amongst rhesus macaques, for example, seems to release tensions among the higher-ups. Bullying seems to reinforce their bonds, a ...
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3288 |
duddy |
7 years ago |
Can you guess the length of a giraffe's tongue?
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Hungry? A snacking giraffe showing off its blue/black tongue, which can grow 45 to 50 cm long. The dark colour protects the species' prehensile tongues from sun damage during long periods of exposure, when its helping the giraffe navigate between thorns and leaves.
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8939 |
duddy |
10 years ago |
Can you spot the camouflaged frogmouth bird?
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The frogmouths are a group of nocturnal birds found from across India and southern Asia to Australia. They are named for their large flattened hooked bills and huge frog-like gape, which they use to take insects. The one's shown above are tawny frogmouths, and they exhibits one of the best examples of cryptic plumage and mimicry, which perch low on tree branches during the day camouflaged as part of the tree. Their silvery-grey plumage patterned with white, black, and brown streaks and spots allows them to freeze into the form of a broken tree branch and become practically invisible in broad daylight. The tawny frogmouth often chooses a broken part of a tree branch and perches upon it with its head thrust upwards at an acute angle using it ...
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1041 |
bio_man |
6 years ago |
Canada's only desert
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You probably wouldn't associate Canada with having any deserts, since the country is typically attributed with winters that are long and harsh. However, that's not entirely true if you visit the southern region of Osoyoos, British Columbia, Canada, known as the Okanagan Desert. In this area, summer temperatures regularly exceed 38˚C (100 °F), and portions of the area receive roughly 250 to 300 mm (10 to 12 inches) of rain per year – compare that to Vancouver, which receives approximately 1120 mm (43 inches) of rain per year. While some areas in British Columbia experience hotter summer temperatures and are at least as arid, the South Okanagan area is home to several species of plants and animals that are not found elsewhere in Canada. For e ...
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19719 |
bio_man |
4 years ago |
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12952 |
duddy |
9 years ago |
Chicken egg colours explained
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It's a common knowledge that different breeds of chickens lay different colored eggs. Here I'll explain what chemicals and conditions give rise to these differences. White eggsAll eggshells are made of calcium carbonate and the white ones have no pigment added.Brown eggsThe brown colour is caused by protoporphyrin IX, from the hen's haemoglobin, and is coated on the outside of the egg as it moves through the oviduct.Blue eggsBlue eggshells have the pigment oocyanin, which does permeate the shell, so the blue coloring will be all the way through.Green eggsIf a brown layer and a blue layer are crossbred, chances are you will get a green egg when the protoporphyrin IX layer is deposited over the blue oocyanin shell.Pink eggsThe pinkish tint ...
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1484 |
bio_man |
6 years ago |
China's spectacular rainbow mountain range
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China's world famous landmarks like the Great Wall and army of terracotta soldiers draw millions of visitors a year but the Middle Kingdom has another drawcard that is equally breath-taking despite being largely unknown.
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5165 |
duddy |
10 years ago |
Commensalism
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Sloths have a commensal relationship with several insects. Their thick fur readily traps bacteria and algae, which makes a good home for many beetles. The beetles are able to lay their eggs in a place that is rich in nutrients upon hatching, and the sloths don’t care either way. One sloth was reported to have over 900 beetles living in its fur!
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4606 |
savio |
10 years ago |
Confusing cat-like animal from Madagascar
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The fossa ( Cryptoprocta ferox) is carnivorous mammal endemic to Madagascar. It is a member of the Eupleridae, a family of carnivorans closely related to the mongoose family. Its classification has been controversial because its physical traits resemble those of cats, yet other traits suggest a close relationship with viverrids (e.g. bearcat). The fossa is the largest mammalian carnivore on the island of Madagascar and has been compared to a small cougar. Adults have a head-body length of 70–80 cm (28–31 in) and weigh between 5.5 and 8.6 kg (12 and 19 lb), with the males larger than the females. It has semi-retractable claws (meaning it can extend but not retract its claws fully) and flexible ankles that allow it to climb up and down tre ...
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6123 |
bio_man |
6 years ago |