Washington, December 20 : A Cornell researcher has adopted a new way to study exactly how birds communicate-recording their songs and then playing them back to other birds of the same species.

Behavioural ecologist Sandra Vehrencamp records bird songs in Santa Rosa National Park, Guanacaste, Costa Rica.

She says that her aim is to decode which elements of bird songs enable them to communicate about mating and reproduction, territorial boundaries, age, and even overall health.

London, December 20 : The BBC has come up with a new version of the iPlayer that works with Mac and Linux computers.

The BBC, which had developed the service to extend its existing RealPlayer-based "Radio Player" and other streamed video clip content, had come under fire for producing a version that only worked with Microsoft''s Windows XP.

The online service, that had gone live on 25 December 2007, used to use Microsoft''s digital rights management (DRM) system to enforce viewing restrictions, reports the Telegraph.

Washington, Dec 20 : Using the controller from the popular Nintendo Wii gaming system, scientists from the Idaho National Laboratory, working with engineers from the U. S. Army, Foster-Miller, and iRobot, are developing novel ways to control military robots.

"If a soldier wants to find a bomb (with a robot), 95 percent of their attention has to be focused on the screen," Doug Few, an engineer at the Idaho National Laboratory (INL) working on the project, told Discovery News.

London, Dec 20 : In order to overcome problems of speed and range encountered with micro air vehicles, scientists have now developed a vertical-takeoff micro aircraft.

Micro air vehicles (MAVs) are uncrewed aircraft with a wingspan of 15 centimetres (5.9 inches) or less and are commonly used by the military or police forces for surveillance.

Most of the MAVs, just like a full-sized airplane, are controlled by conventional moving aerodynamic surfaces such as flaps.

London, Dec 20 : Engineers at the University of Nevada in the US have tested a new design for a flexible bridge that can bounce back after an earthquake.

According to a report in New Scientist, the engineers used three large shake tables to test a 33.5-metre-long, 181-tonne (200-ton) bridge sporting an exotic new design.

The bridge, a quarter-scale replica of its projected real-life size, was subjected to 10 seconds of shaking like that created by an earthquake of magnitude 8.0.

The concrete used in the bridge was reinforced with "smart" nickel titanium - Nitinol - a "shape-memory" alloy commonly used in bendable spectacle frames.

Washington, Dec 20 : A computer model has successfully reproduced the birth of two real tropical cyclones that formed in the Indian Ocean in December 2006 and January 2007.

The model, called the Nonhydrostatic ICosahedral Atmospheric Model (NICAM), was developed for the supercomputer Earth Simulator at JAMSTEC (Japan Agency for Marine-Earth Science and Technology).