Monarch butterflies use magnetic compasses
By S. MiliusMonarchs can check magnetic fields as a backup to their sun compass.
Built-in magnetic compasses may orient Monarch Butterflies during their mind-boggling, southwestern migration, according to new experiments in Kansas.
The butterflies flutter up to 2,500 miles in autumn from breeding grounds in the eastern United States and Canada to a winter haven in Mexico. These millions of migrants are going to a destination not one of them has ever seen.
The generation taking to the air in the fall represents the great-great grandchildren, or even more distant descendants, of the monarchs that left Mexico the previous spring. Yet the new generation returns to the same dozen or so roosting areas that their ancestors used.
Previous studies showed that monarchs can orient by the sun. The new work provides the first direct evidence that monarchs can also sense directions from the magnetic field, according to Orley R. Taylor of the University of Kansas in Lawrence. He, Jason A. Etheredge of Kansas, and their colleagues describe the results in the Nov. 23 Proceedings of the National Academy of Sciences.
"This is not the last word," Taylor says. "What the butterflies are doing is very complicated."
The researchers caught migrating monarchs in fall and released them into a tube, in which they crawled upward to a circular tabletop arena. In a room with no shielding from Earth's magnetic field, most of the butterflies took flight toward the southwest. In a shielded room, however, they flew in random directions.
Next, researchers created a magnetic field oriented in the opposite direction from Earth's. Butterflies then flew northeast, as if their compasses had reversed.
The team studied fall migrants because the same generation flying north in spring gets hard to handle, Taylor says. "They're completing a reproductive death run, like salmon," as he puts it. Females lay eggs daily even though their route covers 1,000 miles. By the end, "they have practically no wings left; they're crawling from plant to plant to lay eggs�it's awesome," Taylor says.
Charles Walcott of Cornell University calls the monarch paper "terrific" and notes that other researchers have been stumped by the challenge of devising a way to test butterflies for magnetic orientation.
For animal compasses, "we used to think there was a single secret," he says, sounding wistful. Studies now show that animals combine methods using "a Chinese-menu approach," Walcott explains. Night-migrating birds, for example, can orient by the sunset glow and star patterns as well as by the magnetic field.
Kenneth P. Able of the State University of New York at Albany says he suspects that magnetic orientation "is a very widespread ability." Honeybees, some wasps, some fish, sea turtles, and even a species of mole rat can take bearings magnetically. Also, "it looks like every migratory bird you test, if you do it right, has a magnetic compass," Able says. However, he points out, discovering a compass takes the scientists just a small step toward explaining how monarchs navigate.
"I'm not sure anybody is ever going to answer that," says Karen S. Oberhauser, who studies monarchs at the University of Minnesota. "Insects sense the world in very different ways from humans. They use things we can't perceive, maybe even things we can't conceive."
Homing pigeons use magnetism through tiny iron crystals in their beaks. Turtles use magnetism by sensing slight differences in magnetism throughout the ocean. It keeps them in the cycle of warm waters in a specific 8,000 mile path that they swim for years.
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to find veins of gold ore
When current flows in a conductor there is a magnetic field formed around the conductor. This magnetic field can be used to make an electric magnet (like the ones used at junkyards), motors also use magnetism to operate, and many switches (solenoid, motor starters, and relay switches) use magnetism to open or close.
The magnetism of a quartz is 3.56
Yes, the "old" televisions use magnetism to controll the movements of the electrons.
No
Penguins use magnetism in order to turn sucrose (a disaccharide) into glucose and fructose (monosaccharides).
Butterflies use their energy in various ways. Butterflies use their energy to eat and to fly around their environments for example.
No
There were migratory butterflies.
They don't, they use wings.
The difference between electricity and magnetism is that you must be in the same frame of reference as the electric field to experience electricity, because all that magnetism is, is electricity moving relative to you.Although they are two different forms of energy, you can use magnetism to create electricity and you can use magnetism to create electricity.Electricity is the flow of energy or current through a metallic substance. Magnetism is the attraction of the metallic molecules in a solid or substance.
no
Yes, it does.
Stick insects and bumble bee's use magnetism to find their way to sticks and honey.
The magnetic hold in coil uses magnetism along with the electric motor that turns the drum.