Agriculture
Where Have All the Bees Gone?
Seeds of the Future
Growing Healthier Tomato Plants
Amphibians
Poison Dart Frogs
Salamanders and Newts
Toads
Animals
Navigating by the Light of the Moon
Fishing for Giant Squid
Ultrasonic Frogs Raise the Pitch
Behavior
Double take
Dino-bite!
Lost Sight, Found Sound
Birds
Crows
Pheasants
Albatrosses
Chemistry and Materials
The metal detector in your mouth
A Butterfly's Electric Glow
The science of disappearing
Computers
Two monkeys see a more colorful world
It's a Small E-mail World After All
Getting in Touch with Touch
Dinosaurs and Fossils
Fossil Fly from Antarctica
A Really Big (but Extinct) Rodent
Watery Fate for Nature's Gliders
E Learning Jamaica
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
Earth
A Dire Shortage of Water
Petrified Lightning
A Grim Future for Some Killer Whales
Environment
A 'Book' on Every Living Thing
Snow Traps
Flu river
Finding the Past
Stone Tablet May Solve Maya Mystery
Stonehenge Settlement
Stone Age Sole Survivors
Fish
Parrotfish
Halibut
Tiger Sharks
Food and Nutrition
The mercury in that tuna
The Color of Health
Turning to Sweets, Fats to Calm the Brain
GSAT English Rules
Subject and Verb Agreement
Who vs. Whom
Whoever vs. Whomever
GSAT Exam Preparation Jamaica
42,000 students will sit for the GSAT Exam in two weeks
How are students placed after passing the GSAT exam
GSAT stars reap scholarship glory
GSAT Exams Jamaica Scholarships
42,000 students will sit for the GSAT Exam in two weeks
2014 GSAT Results for Jamaican Kids
GSAT Exam Preparation
GSAT Mathematics
Detecting True Art
GSAT Mathematics Quiz, Teaching Math, teaching anxiety
Secrets of an Ancient Computer
Human Body
Nature's Medicines
Sleeping Soundly for a Longer Life
Foul Play?
Invertebrates
Clams
Mollusks
Scallops
Mammals
Walrus
Jaguars
Miscellaneous Mammals
Parents
The Surprising Meaning and Benefits of Nursery Rhymes
How children learn
Choosing a Preschool: What to Consider
Physics
Einstein's Skateboard
One ring around them all
IceCube Science
Plants
Fastest Plant on Earth
Bright Blooms That Glow
A Giant Flower's New Family
Reptiles
Crocodilians
Tortoises
Caimans
Space and Astronomy
A Smashing Display
Zooming In on the Wild Sun
Intruder Alert: Sweeping Space for Dust
Technology and Engineering
Roll-Up Computer Monitors to Go
Toy Challenge
Drawing Energy out of Wastewater
The Parts of Speech
What is a Preposition?
Adjectives and Adverbs
Countable and Uncountable Nouns
Transportation
Seen on the Science Fair Scene
Tinkering With the Basic Bike
Flying the Hyper Skies
Weather
A Change in Climate
Science loses out when ice caps melt
Where rivers run uphill
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™