More than 1,200 animal species have evolved the ability to walk on water. Not only small animals such as insects and spiders, some reptiles, birds and even mammals are also developing this talent.
Although there are many techniques for walking on water, but are categorized in two patted and rolled, according to the paper in 2006 from the journal Annual Review of Fluid Mechanics.
Small animals into the categories slide. Insects, like a water spider, can glide or run faster at the surface of the water. These creatures are quite small and its weight can be supported almost entirely by surface tension, which is a relatively weak bonding strength of water molecules together.
For these animals, gliding through the water similar to how humans can be lifted in the trampoline, according to John Bush, a mathematician at the Massachusetts Institute of Technology who specializes in fluid dynamics. When walking on water insects or spiders hit the water, his legs bent and damaged surface, but not until the break. Surface and then bounced back, pushing upward.
Surface tension makes power like that might happen. Water molecules were attached to other water molecules around it, in all directions. However, water-resistant leg is also required. It has a microscopic layer of dense hair on their legs, which can be coated with water-repellent wax. Or hair trap from the air cushion around their feet.
"Without these adaptations, the water will soak the feet like sinking through the trampoline," said Bush.
For larger animals, can walk on water with a pat. The strength of surface tension is too weak to support body weight is greater.
Basilisk lizards, water birds including the Western Grebe and even some dolphins tail can walk on the surface with power and speed sufficient to keep their bodies do not drown.
Basilisk lizard, for example, can run at speeds of more than five meters per second with a tap water with its hind legs. That pushed the water from his feet, and create a small air pocket around the foot. But lizards have to move his feet fast enough, so that the air bag did not close around the legs and dragged him into the water. Small lizards can more easily generate the force needed to lift them out of the water. While the larger must square off on the ground to achieve the momentum required, to support the weight and still survive.
Most animals can only travel a short distance above the water. Some such as the basilisk lizard, do it to avoid predators on land. While others such as fishing spiders for food. And the others do so as part of an elaborate mating ritual, like the Western Grebe.
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