Birds identify points as geographic latitude, longitude

2008-01-31 22:14:04 Xinhua English

BEIJING, Feb. 1 (Xinhuanet) -- Scientists have found that birds could identify at least two coordinates roughly corresponding to geographic latitude and longitude and suggested they are not limited to north-south direction as some had thought, media reported Friday. ;

Russian scientists found Eurasian reed warblers captured during migration and then dumped 1,000 km off course were able to find their way back to their original route, suggesting some birds can truly navigate.

The Russian team said migrating birds such as the warblers might rely on two internal clocks, one to set their "home time" and the other to their wintering grounds. Geomagnetic information might also play a role.

"This finding is surprising and presents a new intellectual challenge to bird migration researchers, namely which cues enable birds to determine their east-west position?" said Nikita Chernetsov at the Zoological Institute in Russia.

"We have experimentally shown beyond reasonable doubt that long-distance, intercontinental avian migrants can correct for east-west displacements during their return migration in spring," Chernetsov said. "This means that they can determine geographic longitude, even though we do not currently know how they do it."

Other studies have suggested that birds use the position of the sun or geomagnetic information to determine latitude, which defines north or south location.