And how do they find their wintering grounds with such pinpoint accuracy? No single answer can satisfy those questions because different species of migratory birds use different homing skills. Also, adult birds emphasize different instincts and cues compared to young birds. Waterfowl such as geese and ducks migrate during daytime, using the path of the sun to keep on course, whereas songbirds such as warblers and orioles move at night, using the stars to stay the right direction.
Many use the magnetic field of the earth to gauge their longitude and latitude and zero in on their destination. This sense gives young birds a path to follow to the appropriate spot.
On this basis, the theory is that they can calculate their position on the grid and correct their orientation. This would mean that birds essentially navigate using a system similar to our Cartesian coordinates — the basis of modern GPS navigation.
If this coordinates theory is accurate, it would mean that birds should be able to use their knowledge of magnetic field parameters to estimate their location anywhere on Earth — through the extrapolation or extension of their navigational rules. To date, however, there has been no clear evidence that birds can use the magnetic field in this way. But our new study on the migratory Eurasian reed warbler — or the Acrocephalus scirpaceus — is the first to show clear evidence that they can in fact do this.
Remarkably, we found that this corresponded to the direction that it would be trying to migrate in the wild, which we know from previous experiments.
However, it has not been confirmed that a magnetic field as weak as Earth's can produce detectable changes within a photochemical molecule; nor, has a photochemical molecule been shown to respond to the direction of such a magnetic field. A new study, funded by the National Science Foundation and detailed online in the April 30, issue of the journal Nature , shows that the photochemical model becomes sensitive to the magnitude and direction of weak magnetic fields similar to Earth's when exposed to light.
A synthesized photochemical molecule composed of linked carotenoid C , porphyrin P and fullerene F units can act as a magnetic compass, the researchers found.
When excited with light, CPF forms a short-lived charge-separated state with a negative charge on the ball-like fullerene unit and a positive charge on the rod-like carotenoid unit. Although often overlooked, plants also have unique behaviors. Two examples of their behaviors include geotropism, the growth of plants against the force of gravity and phototropism, the growth of plants toward the light.
Learn more about these fascinating behaviors with these resources. National Geographic Explorer Pete Marra is an ornithologist, which is a fancy title for someone who studies birds. He started "birding" at six years old and has since dedicated his career to studying birds and figuring out why and how they migrate thousands of kilometers a year.
Pete shows us just how many birds fly through Washington, D. Students watch a video of Kristen Ruegg describing her research on migratory birds. Join our community of educators and receive the latest information on National Geographic's resources for you and your students.
Skip to content. Twitter Facebook Pinterest Google Classroom. Background Info Questions Vocabulary. Many species of birds migrate thousands of kilometers every year. Migration is driven mostly by weather and the availability of food.
In the springtime, birds migrate to temperate regions, where food is plentiful and birds may safely create nests. In autumn, birds migrate to warmer latitude s, following their food sources and more comfortable weather pattern s.
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