Agriculture
Watering the Air
Chicken Eggs as Drug Factories
Fast-flying fungal spores
Amphibians
Newts
Tree Frogs
Salamanders and Newts
Animals
Red Apes in Danger
Blotchy Face, Big-Time Wasp
Lives of a Mole Rat
Behavior
The Science Fair Circuit
A Grim Future for Some Killer Whales
Training Your Brain to Feel Less Pain
Birds
Storks
Condors
A Meal Plan for Birds
Chemistry and Materials
Cold, colder and coldest ice
Sticky Silky Feet
Butterfly Wings and Waterproof Coats
Computers
Galaxies far, far, far away
Supersonic Splash
Graphene's superstrength
Dinosaurs and Fossils
Some Dinos Dined on Grass
Meet your mysterious relative
An Ancient Feathered Biplane
E Learning Jamaica
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Earth
A Dire Shortage of Water
Killer Space Rock Snuffed Out Ancient Life
Petrified Lightning
Environment
Pumping Up Poison Ivy
A Change in Leaf Color
Little Bits of Trouble
Finding the Past
Meet your mysterious relative
Traces of Ancient Campfires
A Volcano's Deadly Ash
Fish
Hammerhead Sharks
Sting Ray
Goldfish
Food and Nutrition
Making good, brown fat
The Essence of Celery
In Search of the Perfect French Fry
GSAT English Rules
Capitalization Rules
Who vs. That vs. Which
Who vs. Whom
GSAT Exam Preparation Jamaica
March 21-22, 2013: Over 43,000 students will take the GSAT Exam
42,000 students will sit for the GSAT Exam in two weeks
GSAT stars reap scholarship glory
GSAT Exams Jamaica Scholarships
Access denied - Disabled boy aces GSAT
GSAT Scholarship
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Mathematics
Play for Science
10 Common Mistakes When Preparing for the GSAT Math Test
Losing with Heads or Tails
Human Body
Sun Screen
Hey batter, wake up!
Dreaming makes perfect
Invertebrates
Roundworms
Hermit Crabs
Flatworms
Mammals
Lhasa Apsos
Squirrels
Moles
Parents
What Not to Say to Emerging Readers
How children learn
Raise a Lifelong Reader by Reading Aloud
Physics
Gaining a Swift Lift
Electric Backpack
Spin, Splat, and Scramble
Plants
Surprise Visitor
The algae invasion
City Trees Beat Country Trees
Reptiles
Geckos
Snakes
Turtles
Space and Astronomy
A Star's Belt of Dust and Rocks
Roving the Red Planet
Cool as a Jupiter
Technology and Engineering
Riding Sunlight
Musclebots Take Some Steps
Shape Shifting
The Parts of Speech
Adjectives and Adverbs
Pronouns
Problems with Prepositions
Transportation
Revving Up Green Machines
Robots on the Road, Again
Ready, unplug, drive
Weather
Watering the Air
Where rivers run uphill
Arctic Melt
Add your Article

Fear Matters

Halloween is a spooky time of year. After hearing all the scary stories and seeing all the scary costumes, you might start to imagine ghosts lurking in the shadows, witches flying across the sky, and skeletons dancing in graveyards. You probably wouldn't be surprised if a goblin jumped out from the bushes during recess and shouted, "BooEven if you've never been afraid of the dark, you might find yourself looking for monsters under the bed and sleeping with a night-light on as the end of October approaches. If so, don't feel you're acting like a coward. It's perfectly normal to change your behavior when you feel afraid. After all, animals do it too. "Fear matters," says Karen Warkentin, a Boston University ecologist. "It's a good thing," she adds, "because fear makes you do things that keep you alive." Spooked frogs Like kids, many animals experience fear. And they respond to the feeling in a variety of ways. Antelope on the plains of Africa, for example, run at the sight of a lion. A frightened turtle pulls its head and legs inside its shell. And small fish swim away when a big, hungry fish approaches. Some animals respond to fear in ways you might not expect. The fear of being eaten, for instance, can scare some frogs right out of their eggs. Warkentin made that surprising discovery several years ago while studying tropical red-eyed treefrogs in Costa Rica. n this species, female frogs attach jellylike clumps of their eggs to the undersides of leaves. The leaves hang on branches that dangle over ponds. When embryos hatch from the jellylike mass of eggs, tadpoles tumble into the water, where they eventually grow into adult frogs. Treefrog eggs usually grow for 6 days before hatching. If the embryos sense that a hungry snake is about to attack, however, they can hatch up to 2 days ahead of schedule. Their snake predators can't swim. So, by falling into the water early, the tadpoles escape the serpents' hungry jaws. How can unborn frogs know that a snake is about to attack? Warkentin looked for an answer to that question by experimenting with frog eggs in her laboratory. An approaching snake, she discovered, produces vibrations separated by brief pauses. When Warkentin shook a clump of frog eggs in a similar pattern, the embryos came tumbling out. Other sound patterns, such as the pitter-patter of rain or the continuous shaking of a landing bird, didn't seem to scare the embryos, and they stayed put. Warkentin concluded that treefrogs can both detect vibrations and recognize when the motion is coming from a snake. If hatching early helps protect red-eyed treefrogs from snakes, you might wonder why their eggs don't always hatch sooner. It turns out that hatching early brings its own dangers. Once tadpoles land in the water, hungry fish, shrimp, and other animals like to eat them too. Staying in their eggs for a full 6 days, then, allows frog embryos to grow big and strong. This extra growth improves their odds of surviving in the water. In a snakefree environment, in other words, it makes the most sense for a frog embryo to wait 6 days before hatching. But, Warkentin points out, "If staying in the egg means you're going to be eaten by a snake, you might as well find out what's in the water." Ecology of fear Fear can do more than affect animal behavior. It can actually influence entire ecosystems, say forest ecologists William Ripple and Robert Beschta of Oregon State University in Corvallis. In Wyoming's Yellowstone National Park, for example, the whole food web shifts when there are wolves around for the elk to worry about. Grey wolves eat elk. And there used to be lots of wolves in the park. Then, in the 1920s, wolves were removed from the area. As a result, the elk population exploded. Aspen trees in the park began to suffer because the large elk population was eating young trees before they had a chance to mature. In the mid-1990s, scientists reintroduced wolves to the park. They expected that elk numbers would drop and aspen numbers would rise. Instead, a surprising sequence of events followed. The elk population declined somewhat, but remained large enough to damage the aspens. Nevertheless, aspen trees returned to parts of the park where they hadn't grown for years, Ripple and colleagues reported last summer. So, how is it that young aspen trees are surviving, even as the elk population continues to thrive? Ripple and Beschta suspect the park's elk change their diets when they face an elevated risk (and fear) of being eaten themselves. Rather than munching on young aspen trees growing near streams, elk are spending more time on hills where they can easily see approaching wolves. Elk are also retreating deeper into the forest, where wolves are less likely to spot them. With wolves back in the ecosystem," Ripple says, "The elk become more wary, more vigilant, and much more careful as to where they go and where they browse and graze." He calls this ecosystem-wide phenomenon an "ecology of fear." It's possible, he says, that similar relationships shape food webs all over the world. "There are probably many interconnections and functions that we don't know about yet," he adds. It's important that wildlife managers recognize that a predator like a wolf can affect plants, even when it doesn't eat them, Ripple says. In Yellowstone, for example, it wasn't necessary to kill elk in order to protect the aspens. Sometimes, Warkentin says, with animals like these, "You just have to scare them."

Fear Matters
Fear Matters








Designed and Powered by HBJamaica.com™