Have you ever seen a lizard hurtling over your head? How about a frog sailing down from the tree tops? I’m not making these animals up. They belong to one of earth’s most astonishing groups of animals.
Gliders travel through the air, but they don’t fly. Instead, they glide. What’s the difference? Well, to get itself off the ground, a bird, bat, or insect has to generate a force called lift. A flying animal generates lift using its wings, which are attached to powerful flight muscles. These wings move and bend in complicated motions to counteract the force of gravity.
Gliding animals do not have muscle-powered wings. Instead, most gliding animals have special flaps or folds of skin called patagia. Like wings, the patagia generate lift—but only after the animal is already moving through the air.
When chased by a snake, a Draco lizard leaps from its tree. Instead of plunging to its death, it spreads out its rib cage into two elegant airfoils covered with skin. As air rushes over them, these airfoils—the patagia—generate lift to keep the lizard from falling straight down. The lizard does steadily descend toward earth, but it is also riding the air. It can change directions, pull a U-turn, and control where it wants to go. In the process it can travel hundreds of feet before landing on another tree or on the ground.
The patagia of Wallace’s frogs lie between their toes. These frogs usually live up in the trees, but when it is time to mate or lay eggs, they leap, spread out their toes, and glide to earth.
Earth’s most astonishing gliders may be five species of gliding snakes. These snakes don’t have patagia. Instead, they flatten out their bodies and “crawl” through the air. Scientists aren’t sure if the crawling motion helps generate lift, or if lift comes mainly from a snake’s flattened shape, but the animals can glide more than 100 feet before landing.
Most of earth’s gliding animals live in Southeast Asian rainforests, which are home to more than eighty species of gliding lizards, frogs, snakes, and mammals. In North America, we have only two gliding animals: Northern and Southern flying squirrels. Despite their name, flying squirrels don’t fly. They glide—and are adorably cute! Want to see one? Try shining a flashlight on a bird feeder at night!
A male Draco lizard extending his gular flag (throat flap) and patagi (wings). While not capable of powered flight Dracos often obtain lift in the course of their gliding flights. Glides as long as 200 feet have been recorded, Wikimedia
Wallace's frogs live almost exclusively in the trees, and leap and "fly" from tree to tree or to bushes. The membranes between their toes and loose skin flaps on their sides catch the air as they fall, helping them to glide, sometimes 50 feet or more, to a neighboring tree branch or even all the way to the ground. They also have oversized toe pads to help them land softly and stick to tree trunks. Wikimedia
Flying squirrels are able to glide from one tree to another with the aid of a patagium, a furry, parachute-like membrane that stretches from wrist to ankle. Their long tail provides stability in flight. Wikimedia
There are five recognized species of flying snake, found from western India to the Indonesian archipelago. They flatten out their bodies and parachute or glide using their ribs to become flat, and then they whip their bodies in a fast, rhythmic S-shape to stay airborne. Wikimedia
Illustrated with arresting photographs, Sneed B. Collard's Catching Air: Taking the Leap with Gliding Animals takes us around the world to learn why so many gliders live in Southeast Asia, and to find out why this gravity-defying ability has evolved in Draco lizards, snakes, and frogs as well as mammals. Why do gliders stop short of flying, how did bats make that final leap, and how did Homo sapiens bypass evolution to glide via wingsuits and hang gliders―or is that evolution in another guise?
MLA 8 Citation
Collard, Sneed B., III. "Meet Earth's Incredible Gliders." Nonfiction Minute,
iNK Think Tank, 11 Apr. 2018, www.nonfictionminute.org/
Henry VIII gets a lot of bad press notably for his seven wives and a regrettable habit of chopping off heads. But there were two Henrys: early and late. Early Henry was a humdinger.
He became king at age 17 in 1509, a big (over six feet) handsome lad. He was broadly educated and well-read in English, Latin, and French. He played the lute, organ, and harpsichord, composed music, and sang well. He loved a party, and he was a ferocious sportsman. Henry played excellent tennis, was a skilled wrestler, hunter, and jouster.
His love of jousting may have been his undoing. This was not a battle skill but a royal game: on huge horses, in heavy armor, opponents rode at each other with blunt lances to knock each other out of the saddle. But in 1536 Henry left his face-covering visor up during a joust, catching a lance on his forehead. His majesty went down under his horse. His legs were crushed and he lay unconscious for two hours, apparently a serious concussion.
Henry changed radically. The broken long bones in his legs healed poorly and developed infected ulcers, which had to be drained using red hot probes. Ouch. Walking became difficult and painful, and finally impossible. The smell from his infected legs was awful. He became angry, paranoid, and irrational. No longer active, he ate and ate, bloating from around 210 pounds (95 kg) to 400 pounds (181 kg). This was late Henry: obese, dangerous, and smelly. His altered mental state and his constant pain surely contributed to his marital difficulties and to steady employment for head-choppers.
A mental, physical wreck, Henry VIII died at age 55 in 1547. Court embalmers replaced his innards with sawdust, resin and herbs to preserve the body, but Henry was already rotting from the legs up. The royal corpse was placed in a sealed lead coffin. An enormous regal procession set off from Whitehall Castle to Windsor Castle. The funeral parade halted the first day at the old Syon Abbey. In the middle of the night, the lead coffin exploded!
Or did it? Some historians suggest that it simply broke because Henry was too fat and the roads were bad. Yet contemporary morticians insist that gasses of decomposition can blow open even a modern sealed coffin. The coffin was soldered shut and the parade hustled on to the burial at Windsor, an untidy end for a wonderful and terrible king.
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The NCSS-CBC Notable Social Studies Committee is pleased to inform you
that 30 People Who Changed the World has been selected for Notable Social Studies Trade Books for Young People 2018, a cooperative project of the National Council for the Social Studies (NCSS) & the Children’s Book Council